Allow configurable CONNECT_LOG4J_LOGGERS in connect images

We would really like to get rid of the appender from log4j.rootLogger via CONNECT_LOG4J_LOGGERS environment variable (as in Confluent images), because it is not possible (so far as we can find) to manage these extra log files with docker.  We are facing out of space issues because of this.  We are able to manage all OTHER log file rotation with these docker-compose settings:

    logging:
        driver: "json-file"
        options:
            max-file: "5"
            max-size: "10m"

We would rather not roll our own image to solve for this one issue, when it seems like a pretty basic need.

Here is what Confluent provides: https://docs.confluent.io/current/installation/docker/operations/logging.html

I have created a PR to allow something like this, but it is slightly different, for Debezium's images: https://github.com/debezium/docker-images/pull/187

This is probably incomplete.  I am not sure if I am supposed to only make this change to 1.3.  Also not sure about if we would want the CONNECT_ prefix or not.  Would appreciate feedback.  Thanks!