Fixes: #9695 Issue link: https://github.com/spring-projects/spring-integration/issues/9695 The `txSize` in the `SimpleMessageListenerContainer` has been replaced with more reasonable `batchSize`. Spring Integration XML support for AMQP module has missed to fix this change: we didn't have a respective test. * Deprecate `tx-size` (will be removed in `6.5`) XML attribute for the `<amqp:inbound-channel-adapter>` and introduce `batch-size` * Cover with the tests * Fix docs from `tx-size` to `batch-size` **Auto-cherry-pick to `6.3.x`**