Add the resource key to the build view.

endpoints/api.py

@@ -1150,6 +1150,7 @@ def build_status_view(build_obj, can_write=False):
     'job_config': json.loads(build_obj.job_config) if can_write else None,
     'is_writer': can_write,
     'trigger': trigger_view(build_obj.trigger),
+    'resource_key': build_obj.resource_key,
   }