72e2aeec2a
Resolves https://github.com/spring-cloud/spring-cloud-stream-binder-kafka/issues/305 Resolves https://github.com/spring-cloud/spring-cloud-stream-binder-kafka/issues/308 Requires https://github.com/spring-projects/spring-integration-kafka/pull/196 `ProducerConfigurationMessageHandler` overrode `handleMessageInternal` to support producer-initiated transactions. Now that the superclass extends `ARPMH`, this method is no longer overridable. Spring Integration Kafka's `KafkaProducerMessageHandler` now detects a transactional `KafkaTemplate` and will automatically start a transaction if needed, so there is no longer any need to override that method. No additional tests needed; see `KafkaTransactionTests`.