Pub/Sub: add region to command to run Dataflow job (#5157)
Pub/Sub: add region to command to run Dataflow job (#5157)

Fixes internal b/164138878.




GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples