Add region tags for getting config. (GoogleCloudPlatform#1301)

* Add region tags for getting config.

* Update cloudiot_http_example.py

* Update cloudiot_http_example.py

Author: noerog

iot/api-client/http_example/cloudiot_http_example.py

@@ -97,6 +97,7 @@ def publish_message(
 @retry.Retry(
     predicate=retry.if_exception_type(AssertionError),
     deadline=_BACKOFF_DURATION)
+# [START iot_http_getconfig]
 def get_config(
         version, message_type, base_url, project_id, cloud_region, registry_id,
         device_id, jwt_token):
@@ -118,6 +119,7 @@ def get_config(
         raise AssertionError('Not OK response: {}'.format(resp.status_code))
 
     return resp
+# [END iot_http_getconfig]
 
 
 def parse_command_line_args():