Regenerate the README files and fix the Open in Cloud Shell link for some samples [(#1441)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/1441)
Regenerate the README files and fix the Open in Cloud Shell link for some samples [(#1441)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/1441)


googleapis/python-pubsub,googleapis/python-pubsub