Migrate telemetry_perf_unittests from KitKat Phone Tester (rel) to KitKat Phone Tester (dbg)

This suite is a bit flaky on CQ, so we are moving it to the main waterfall.
The fact that this is a dbg build also give us some clue to cause of the flakes.

Bug: 791800
Change-Id: I0aa36d80e1de4683a6b6765363654eb7c282b4bc
Reviewed-on: https://chromium-review.googlesource.com/812166Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Ned Nguyen <nednguyen@google.com>
Cr-Commit-Position: refs/heads/master@{#522468}

testing/buildbot/chromium.android.json

@@ -2150,6 +2150,23 @@
         "test": "viz_unittests"
       }
     ],
+    "isolated_scripts": [
+      {
+        "isolate_name": "telemetry_perf_unittests",
+        "name": "telemetry_perf_unittests",
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "device_os": "KTU84P",
+              "device_type": "hammerhead"
+            }
+          ],
+          "hard_timeout": 960,
+          "shards": 12
+        }
+      }
+    ],
     "junit_tests": [
       {
         "test": "base_junit_tests"
@@ -3674,28 +3691,6 @@
         "test": "viz_unittests"
       }
     ],
-    "isolated_scripts": [
-      {
-        "args": [
-          "--browser=android-chromium",
-          "--device=android"
-        ],
-        "isolate_name": "telemetry_perf_unittests",
-        "name": "telemetry_perf_unittests",
-        "swarming": {
-          "can_use_on_swarming_builders": true,
-          "dimension_sets": [
-            {
-              "device_os": "KTU84P",
-              "device_type": "hammerhead",
-              "temp_band": "<30"
-            }
-          ],
-          "hard_timeout": 1500,
-          "shards": 15
-        }
-      }
-    ],
     "junit_tests": [
       {
         "test": "base_junit_tests"

testing/buildbot/waterfalls.pyl

@@ -178,6 +178,7 @@
       'KitKat Phone Tester (dbg)': {
         'test_suites': {
           'gtest_tests': 'chromium_android_gtests',
+          'isolated_scripts': 'telemetry_perf_unittests_isolated_scripts',
           'junit_tests': 'chromium_junit_tests',
         },
         'swarming': {
@@ -197,7 +198,6 @@
         ],
         'test_suites': {
           'gtest_tests': 'chromium_android_gtests',
-          'isolated_scripts': 'telemetry_perf_unittests_isolated_scripts',
           'junit_tests': 'chromium_junit_tests',
         },
         'swarming': {