Switching Base Docker Image to UBI

[krishvoor]

The base image is built upon CentOS 7, thus resultant docker images which leverages kafka-base are also on CentOS 7, which is older than UBI 8. It would be better to equip UBI 8 ( latest and greatest ) and continue the builds, to ensure we are leveraging newer versions/capabilities of dependent packages coming from OS libraries or otherwise.

[scholzj]

We are thinking about this. But I do not think it really has newer packages per-se. Especially with Java based applications which anyway rely mostly on JDK and you can have the same JDK version on both.