Subscription to topics with regex not working for non-persisten topics

Messages on non-persistent topics are not received when using a regex subscription.
This problem is encountered when using a Pulsar IO custom connector (sink).

When using persistent topics the subscription is working as expected

**Expected behavior**
Records are received when subscribing to regex topics.

**Additional context**
Issues #2009
https://github.com/apache/pulsar/issues/2009

Issues #2025
https://github.com/apache/pulsar/issues/2025

Does not solve this problem

@merlimat @sijie

No file or test is identified in the issue. Start by reproducing regex subscription behavior for persistent and non-persistent topics in the Pulsar IO custom connector sink context, then review related issues #2009 and #2025. Done means records are received from non-persistent topics through a regex subscription.

Written by the indexing model from the issue text.