feat: Support this role in container environments

Feature: Support running the firewall role in system container
environments.

Result: These flags enable running the "classic rpm" scenarios in CI,
which ensures that the role works in podman system containers.

Note: This role does *not* work (yet) during container builds such as
bootc "buildah" environments. Thus do not yet add the "containerbuild"
tag.

Author: martinpitt

meta/main.yml

@@ -22,3 +22,4 @@ galaxy_info:
     - fedora
     - firewall
     - system
+    - container