Kafka MessageHandler Does Not Synchronize with a non-Kafka TM for Producer-Only Transactions

[garyrussell]

TransactionSynchronizationManager.getResource() returns null when there is an existing synchronizing transaction, so we run in a local transaction.

https://stackoverflow.com/questions/68460690/wrapping-streambridge-send-and-jpa-save-inside-a-transaction/68461298#68461298

[artembilan]

Looks like we just can call this.kafkaTemplate.inTransaction() instead of something local artificial...