Create a new GN target //services/service_junit_tests, and enable it in bots.

testing/buildbot/chromium.linux.json

 {
   "Android Arm64 Builder (dbg)": {
     "additional_compile_targets": [
       "all"
     ]
   },
   "Android Builder": {
     "additional_compile_targets": [
       "cronet_test_instrumentation_apk",
       "system_webview_apk"
@@ skipping 1515 matching lines @@
       {
         "test": "device_junit_tests"
       },
       {
         "test": "junit_unit_tests"
       },
       {
         "test": "net_junit_tests"
       },
       {
+        "test": "service_junit_tests"
+      },
+      {
         "test": "ui_junit_tests"
       },
       {
         "test": "webapk_client_junit_tests"
       },
       {
         "test": "webapk_shell_apk_junit_tests"
       }
     ]
   },
@@ skipping 1535 matching lines @@
       {
         "test": "device_junit_tests"
       },
       {
         "test": "junit_unit_tests"
       },
       {
         "test": "net_junit_tests"
       },
       {
+        "test": "service_junit_tests"
+      },
+      {
         "test": "ui_junit_tests"
       },
       {
         "test": "webapk_client_junit_tests"
       },
       {
         "test": "webapk_shell_apk_junit_tests"
       }
     ]
   },
@@ skipping 2046 matching lines @@
         "isolate_name": "telemetry_unittests",
         "name": "telemetry_unittests",
         "swarming": {
           "can_use_on_swarming_builders": true,
           "shards": 4
         }
       }
     ]
   }
 }