Since sharing variables amongst roles has been made default since
Ansible 2.6, private option has been deprecated; so stop using it.
Signed-off-by: Rishabh Dave <ridave@redhat.com>
Use podman or docker wether they are available or not. podman will be
prioritized over docker if present.
Signed-off-by: Sébastien Han <seb@redhat.com>