chromium_tests: apply chromium.get_env() when running tests

scripts/slave/recipes/findit/chromium/test.expected/unaffected_test_skipped_by_analyze.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[build]\\scripts\\slave\\kill_processes.py"
     ],
     "name": "taskkill"
   },
   {
@@ skipping 789 matching lines @@
       "--tag",
       "slavename:build1-a1",
       "--tag",
       "stepname:affected_tests (r1) on Windows-7-SP1",
       "--idempotent",
       "[dummy hash for affected_tests]",
       "--",
       "--gtest_filter=Test.One",
       "--test-launcher-summary-output=${ISOLATED_OUTDIR}/output.json"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json"
+    },
     "name": "test r1.[trigger] affected_tests (r1) on Windows-7-SP1",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"base_task_name\": \"affected_tests (r1)/Windows-7-SP1/[dummy has/win_chromium_variable/1\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"tasks\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"affected_tests (r1)/Windows-7-SP1/[dummy has/win_chromium_variable/1\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"shard_index\": 0, @@@",
       "@@@STEP_LOG_LINE@json.output@      \"task_id\": \"10000\", @@@",
       "@@@STEP_LOG_LINE@json.output@      \"view_url\": \"https://chromium-swarm.appspot.com/user/task/10000\"@@@",
@@ skipping 21 matching lines @@
       "--",
       "collect",
       "--swarming",
       "https://chromium-swarm.appspot.com",
       "--decorate",
       "--print-status-updates",
       "--shards",
       "1",
       "affected_tests (r1)/Windows-7-SP1/[dummy has/win_chromium_variable/1"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json"
+    },
     "name": "test r1.affected_tests (r1) on Windows-7-SP1",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[build::test_results]\\resources\\upload_gtest_test_results.py",
       "--input-gtest-json",
       "{\"per_iteration_data\": [{\"Test.One\": [{\"elapsed_time_ms\": 0, \"output_snippet\": \"\", \"status\": \"SUCCESS\"}]}]}",
       "--master-name",
       "tryserver.chromium.win",
       "--builder-name",
       "win_chromium_variable",
       "--build-number",
       "1",
       "--test-type",
       "test r1.affected_tests (r1) on Windows-7-SP1",
       "--test-results-server",
       "test-results.appspot.com",
       "--chrome-revision",
       "170242"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json"
+    },
     "name": "test r1.Upload to test-results [test r1.affected_tests (r1) on Windows-7-SP1]",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[build]\\scripts\\slave\\process_dumps.py",
       "--target",
       "Release"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json"
+    },
     "name": "test r1.process_dumps",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "import sys; sys.exit(0)"
@@ skipping 20 matching lines @@
       "@@@STEP_LOG_END@report@@@",
       "@@@SET_BUILD_PROPERTY@report@{\"metadata\": {\"regression_range_size\": 1}, \"result\": {\"r1\": {\"affected_tests\": {\"status\": \"passed\", \"valid\": true}, \"unaffected_tests\": {\"status\": \"skipped\", \"valid\": true}}}}@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]