Outer Loop: Java Container Image should be updated

[jaxx0r]

RHEL 7 based images will be EOL very soon.
Also there is some confusion around which images are now actually used.
in chapter "Create an ImageStream Tag with an Old Image Version", description hints at OpenJDK 8 based on UBI 8, actual tags point to JDK11 on RHEL7.

Old images are good for vulnerabilities in later scenarios, but we may want to switch to more current "old" images.
The default image already shows critical and fixable issues in Quay, maybe then there is no need to introduce an even older image?