In order to enable testing on rel-eng images, it's necessary to properly
change the way lorax-composer packages are installed (in Makefile and
vm.install script).
Related: rhbz#1810711
The same change has been made in the live ISO test, so keep this change uniform
also in the test_repos_sanity.sh test and vm.install script.
Related: rhbz#1828808
It's not possible anymore to use latest-RHEL-$major in the URLs, it's necessary
to also supply the minor version for rel-eng composes. Also the URL structure
had to be updated due to changes on the download servers.
Related: rhbz#1828808
Note: use podman-docker to avoid changing tests too much. This
is also what we have on the RHEL branches.
There's no service to be started/restarted so remove everything
related to docker service.
Cherry-picked from e1b45958f4
Related: rhbz#1770193
