Support SELinux in enforcing mode on RHEL 8/CentOS 8/Rocky Linux 8.
Add support for SELinux ("Security Enhanced Linux)") in enforcing mode
on RHEL/CentOS 8.
This job is filed now as it's not yet clear whether changes in
the Helix Installer will be reuqired for this, or if the problem
can be solved entirely within the SDP.