Offsets are not advanced in a CDB deployment with low frequency of changes to PDB

Due to a regression introduced by DBZ-5648, there are some situations where when using the Oracle connector with a pluggable database deployment (CDB) that has low volumes of changes, the connector offsets may fail to advance as often as they should.

This regression is due to transaction start/commit/rollback operations only observed from the PDB being captured rather than the entire database. In a database where the PDB may change much less frequently than the root or other pluggable databases, this can lead to situations where the offsets may become stale.

As a temporary workaround, the heartbeat.action.query feature can be enabled to cause the connector to receive an event from the PDB regularly to facilitate the advancement of the offsets until this query issue is resolved.