autotest: skylab_staging: fetch child results of task_run_id

BUG=chromium:966518
TEST=None

Change-Id: I7d7043c279c6f58939a400fb153048b48d2723f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/1626182
Commit-Queue: Aviv Keshet <akeshet@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: C Shapiro <shapiroc@chromium.org>
diff --git a/venv/skylab_staging/test_push.py b/venv/skylab_staging/test_push.py
index d62219c..038deb0 100644
--- a/venv/skylab_staging/test_push.py
+++ b/venv/skylab_staging/test_push.py
@@ -181,9 +181,9 @@
                            service_account_json, suite, require_success=True):
   """Create and wait for a skylab suite (in staging).
 
-  Returns: string task request id of the completed suite.
+  Returns: string task run id of the completed suite.
 
-  Raises: errors.TestPushError if the suite failed.
+  Raises: errors.TestPushError if the suite failed and require_success is True.
   """
   mins_remaining = int((deadline - time.time())/60)
   cmd = [
@@ -219,7 +219,7 @@
       not json.loads(cmd_result.output)['task-result']['success']):
     raise errors.TestPushError('Suite %s did not succeed.' % suite)
 
-  return task_id
+  return json.loads(cmd_result.output)['task-result']['task-run-id']
 
 
 def _verify_test_results(task_id, expected_results):