cdap-kafka-server simply stops if the kafka.server.log.dirs is not writable

If the configured directory 'kafka.server.log.dirs' is not writable by the cdap user, then the cdap kafka server simply stops without any warning/error message indicating the reason.
The cause of the error can be very time-consuming to debug.
Instead, cdap should log a proper error message in this case (perform a file-write check if it needs to).