[Demo] Google Cloud Pub/Sub Connector for Apache Pulsar

Learn how to quickly get started with Google Cloud Pub/Sub Connector for Apache Pulsar.

[tianzicai]

Nice work!
The first few synchronous "pulls" from the newly created Pub/Sub subscription did not work because the first "hello" was published before the subscription was created.
Generally, synchronous "pull" is guaranteed to return messages even if you set how many messages you want to receive.