Added better counters to surosinkstat for KafkaSinkV2

These new counters are important for testing and monitoring a production deployment.
Rather than having to set failure in every catch clause, consider initializing it to true and then setting it to false at the end of the try block.  This would reduce the chance of somebody in the future adding a new catch block and not setting the flag correctly.

Similar suggestion for retry flag, initialize it to true and then set it to false here.