Add `ConversionException` in `FailedRecordProcessor.classifier` to skip retrying

[bananayong]

Affects Version(s): 2.5.4

Hi, I would like to request a convenience feature.
I am writing a kafka listener which need json deserialization.
I learned that spring-kafka support JsonDeserializer and JsonMessageConverter.
And, I did choose JsonMessageConverter because it's more flexible.

The problem is when using JsonMessageConverter, if deserialization fails, it keeps to retry because ConversionExceptionis not in exception classifications of FailedRecordProcessor
I solved this issue through errorHandler.addNotRetryableException(ConversionException.class)
But, It will be nice if ConversionException is in exception classifications by default

Please, Consider to add ConversionException in exception classifications

Thank you!

[garyrussell]

Thanks; yes; really the converter should throw a MessageConversionException (which is already in the default list) but that would be a breaking change now. So, yes, we'll add ConversionException to the default list.

[bananayong]

If you don't mind, can I get this issue for a contribution?

[garyrussell]

Sure. That would be great.

[garyrussell]

Thanks for the contribution!

Cherry-picked to 2.5.x after resolving conflicts.