Add configs for chromeos-betty-pi-arc-google-rel builder and optional trybot

Add mb configs and test configs for chromeos-betty-pi-arc-google-rel and its
optional trybot chromeos-betty-pi-arc-chrome

R=bpastene@chromium.org

Bug: 1000513
Change-Id: I7e64bd4c547b764ce5f5344711bff7232e941bc1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1788302Reviewed-by: Ben Pastene <bpastene@chromium.org>
Commit-Queue: Anushruth  <anushruth@chromium.org>
Cr-Commit-Position: refs/heads/master@{#696861}

testing/buildbot/generate_buildbot_json.py

@@ -1050,6 +1050,7 @@ class BBJSONGenerator(object):
       # Defined in internal configs.
       'chromeos-amd64-generic-google-rel',
       'chromeos-betty-google-rel',
+      'chromeos-betty-pi-arc-google-rel',
       'chromeos-kevin-google-rel',
       # code coverage, see https://crbug.com/1000367.
       'linux-chromeos-coverage-rel-dummy',

testing/buildbot/waterfalls.pyl

@@ -35,6 +35,24 @@
           ],
         },
       },
+      'chromeos-betty-pi-arc-google-rel': {
+        'additional_compile_targets': [
+          'chromiumos_preflight',
+        ],
+        'test_suites': {
+          'gtest_tests': 'chromeos_device_friendly_gtests',
+          'isolated_scripts': 'chromeos_isolated_scripts',
+        },
+        'swarming': {
+          'dimension_sets': [
+            {
+              'kvm': '1',
+              'os': 'Ubuntu-16.04',
+              'pool': 'chrome.tests.cros-vm',
+            },
+          ],
+        },
+      },
       'chromeos-kevin-google-rel': {
         'additional_compile_targets': [
           'chromiumos_preflight',

tools/mb/mb_config.pyl

@@ -16,6 +16,7 @@
     'chrome': {
       'chromeos-amd64-generic-google-rel': 'official_cros_chrome_sdk',
       'chromeos-betty-google-rel': 'official_cros_chrome_sdk_headless_ozone',
+      'chromeos-betty-pi-arc-google-rel': 'official_cros_chrome_sdk_headless_ozone',
       'chromeos-kevin-google-rel': 'official_cros_chrome_sdk_headless_ozone',
       'linux-chromeos-google-rel': 'official_goma_chromeos_minimal_symbols',
       'linux-google-rel': 'official_goma',
@@ -713,6 +714,7 @@
 
     'tryserver.chrome': {
       'chromeos-betty-chrome': 'official_cros_chrome_sdk_headless_ozone',
+      'chromeos-betty-pi-arc-chrome': 'official_cros_chrome_sdk_headless_ozone',
       'chromeos-kevin-chrome': 'official_cros_chrome_sdk_headless_ozone',
       'linux-chrome': 'official_goma',
       'linux-chromeos-chrome': 'official_goma_chromeos_minimal_symbols',