Fix: Fix molecule test errors for latest ansible

Fix: Fix molecule test errors for latest ansible

This include:
* Use MOLECULE_PLATFORM_NAME rather than MOLECULE_DISTRO to run tests
  per distro.
* Remove "warn" arg from command actions, as it is no longer
  supported.
* Replace generic "package" with "yum" and "apt".
* Specify ansible.builtin.command for action using a register. There
  was an error caused by a missing field from the registered output
  otherwise.
* Fix list concat formatting for package list in vars/.
* Add gpg to package list. Some docker images do not come with it
  included, which was causing failures.

Issue: RELENG-5129
Change-Id: I0a665f11f6f592ed2fe1ec2875a6db9e758e91cf
Signed-off-by: Eric Ball <eball@linuxfoundation.org>