Add os:Android to all android swarming tests.

The "os" tag is needed to trigger the following condition:
https://codesearch.chromium.org/chromium/build/scripts/slave/recipe_modules/chromium_tests/steps.py?rcl=7d066dd6eac24ac19a1fb1c4f1bc7dd432d433c0&l=1339

That will correctly add the device type to all trigger steps in recipes.
(Purely a QoL change.)

Change-Id: I38d318a0d3814426e5ac8e1e16fd38955e0186fc
Reviewed-on: https://chromium-review.googlesource.com/1086290
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565127}

testing/buildbot/chromium.swarm.json

@@ -29,7 +29,8 @@
           "dimension_sets": [
             {
               "device_os": "KTU84P",
-              "device_type": "hammerhead"
+              "device_type": "hammerhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -72,7 +73,8 @@
           "dimension_sets": [
             {
               "device_os": "KTU84P",
-              "device_type": "hammerhead"
+              "device_type": "hammerhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -116,7 +118,8 @@
           "dimension_sets": [
             {
               "device_os": "KTU84P",
-              "device_type": "hammerhead"
+              "device_type": "hammerhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -160,7 +163,8 @@
           "dimension_sets": [
             {
               "device_os": "KTU84P",
-              "device_type": "hammerhead"
+              "device_type": "hammerhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -204,7 +208,8 @@
           "dimension_sets": [
             {
               "device_os": "KTU84P",
-              "device_type": "hammerhead"
+              "device_type": "hammerhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -248,7 +253,8 @@
           "dimension_sets": [
             {
               "device_os": "KTU84P",
-              "device_type": "hammerhead"
+              "device_type": "hammerhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -292,7 +298,8 @@
           "dimension_sets": [
             {
               "device_os": "KTU84P",
-              "device_type": "hammerhead"
+              "device_type": "hammerhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -340,7 +347,8 @@
           "dimension_sets": [
             {
               "device_os": "MMB29Q",
-              "device_type": "bullhead"
+              "device_type": "bullhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -384,7 +392,8 @@
           "dimension_sets": [
             {
               "device_os": "MMB29Q",
-              "device_type": "bullhead"
+              "device_type": "bullhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -428,7 +437,8 @@
           "dimension_sets": [
             {
               "device_os": "MMB29Q",
-              "device_type": "bullhead"
+              "device_type": "bullhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -472,7 +482,8 @@
           "dimension_sets": [
             {
               "device_os": "MMB29Q",
-              "device_type": "bullhead"
+              "device_type": "bullhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -516,7 +527,8 @@
           "dimension_sets": [
             {
               "device_os": "MMB29Q",
-              "device_type": "bullhead"
+              "device_type": "bullhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -560,7 +572,8 @@
           "dimension_sets": [
             {
               "device_os": "MMB29Q",
-              "device_type": "bullhead"
+              "device_type": "bullhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -604,7 +617,8 @@
           "dimension_sets": [
             {
               "device_os": "MMB29Q",
-              "device_type": "bullhead"
+              "device_type": "bullhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,
@@ -648,7 +662,8 @@
           "dimension_sets": [
             {
               "device_os": "MMB29Q",
-              "device_type": "bullhead"
+              "device_type": "bullhead",
+              "os": "Android"
             }
           ],
           "expiration": 10800,

testing/buildbot/waterfalls.pyl

@@ -98,6 +98,7 @@
             {
               'device_os': 'KTU84P',
               'device_type': 'hammerhead',
+              'os': 'Android',
             },
           ],
         },
@@ -114,6 +115,7 @@
             {
               'device_os': 'KTU84P',
               'device_type': 'hammerhead',
+              'os': 'Android',
             },
           ],
         },
@@ -128,6 +130,7 @@
             {
               'device_os': 'KTU84P',
               'device_type': 'hammerhead',
+              'os': 'Android',
             },
           ],
         },
@@ -180,6 +183,7 @@
             {
               'device_os': 'KTU84P',
               'device_type': 'hammerhead',
+              'os': 'Android',
             },
           ],
         },
@@ -198,6 +202,7 @@
             {
               'device_os': 'MMB29Q',
               'device_type': 'bullhead',
+              'os': 'Android',
             },
           ],
         },
@@ -213,6 +218,7 @@
             {
               'device_os': 'KTU84P',
               'device_type': 'hammerhead',
+              'os': 'Android',
             },
           ],
         },
@@ -227,6 +233,7 @@
             {
               'device_os': 'KTU84Z',
               'device_type': 'flo',
+              'os': 'Android',
             },
           ],
           'expiration': 10800,
@@ -242,6 +249,7 @@
             {
               'device_os': 'LMY48I',
               'device_type': 'hammerhead',
+              'os': 'Android',
             },
           ],
           'expiration': 10800,
@@ -258,6 +266,7 @@
             {
               'device_os': 'LMY49B',
               'device_type': 'flo',
+              'os': 'Android',
             },
           ],
           'expiration': 10800,
@@ -275,6 +284,7 @@
             {
               'device_os': 'MMB29Q',
               'device_type': 'bullhead',
+              'os': 'Android',
             },
           ],
           'hard_timeout': 960,
@@ -290,6 +300,7 @@
             {
               'device_os': 'MRA58Z',
               'device_type': 'flo',
+              'os': 'Android',
             },
           ],
           'expiration': 10800,
@@ -306,6 +317,7 @@
               'android_devices': '1',
               'device_os': 'NMF26U',
               'device_type': 'marlin',
+              'os': 'Android',
             },
           ],
           'hard_timeout': 1800,
@@ -327,6 +339,7 @@
             {
               'device_os': 'KTU84P',
               'device_type': 'hammerhead',
+              'os': 'Android',
             },
           ],
         },
@@ -349,6 +362,7 @@
             {
               'device_os': 'KTU84P',
               'device_type': 'hammerhead',
+              'os': 'Android',
             },
           ],
         },
@@ -360,6 +374,7 @@
             {
               'device_os': 'KTU84P',
               'device_type': 'hammerhead',
+              'os': 'Android',
             },
           ],
           'expiration': 36000,
@@ -377,6 +392,7 @@
             {
               'device_os': 'NRD91N',
               'device_type': 'bullhead',
+              'os': 'Android',
             },
           ],
           'expiration': 10800,
@@ -393,6 +409,7 @@
             {
               'device_os': 'OPR3.170623.008',
               'device_type': 'marlin',
+              'os': 'Android',
             },
           ],
         },
@@ -424,6 +441,7 @@
           'dimension_sets': [
             {
               'device_type': 'coho',
+              'os': 'Android',
             },
           ],
         },
@@ -439,6 +457,7 @@
           'dimension_sets': [
             {
               'device_type': 'gce_x86',
+              'os': 'Android',
             },
           ],
         },
@@ -581,6 +600,7 @@
             {
               'device_os': 'KTU84P',
               'device_type': 'hammerhead',
+              'os': 'Android',
             },
           ],
         },
@@ -591,6 +611,7 @@
           'dimension_sets': [
             {
               'device_type': 'coho',
+              'os': 'Android',
             },
           ],
         },
@@ -616,6 +637,7 @@
             {
               'device_os': 'MMB29Q',
               'device_type': 'bullhead',
+              'os': 'Android',
             },
           ],
         },
@@ -2293,6 +2315,7 @@
             {
               'device_os': 'MMB29Q',
               'device_type': 'bullhead',
+              'os': 'Android',
             },
           ],
           'hard_timeout': 3600,
@@ -2331,6 +2354,7 @@
           'dimension_sets': [
             {
               'device_type': 'coho',
+              'os': 'Android',
             },
           ],
         },
@@ -2364,6 +2388,7 @@
             {
               'device_os': 'MMB29Q',
               'device_type': 'bullhead',
+              'os': 'Android',
             },
           ],
           'hard_timeout': 960,
@@ -2790,6 +2815,7 @@
             {
               'device_os': 'MMB29Q',
               'device_type': 'bullhead',
+              'os': 'Android',
             },
           ],
         },
@@ -2856,6 +2882,7 @@
             {
               'device_os': 'KTU84P',
               'device_type': 'hammerhead',
+              'os': 'Android',
             },
           ],
           'expiration': 10800,
@@ -2871,6 +2898,7 @@
             {
               'device_os': 'MMB29Q',
               'device_type': 'bullhead',
+              'os': 'Android',
             },
           ],
           'expiration': 10800,