Generate tarballs for neutron-*aas on tags

openstack/neutron-*aas git repository are the result of a split from
neutron. Tarballs will be published as part of the release process on
milestones and final releases, and attached to the same Launchpad page
as Neutron itself.

To that effect, we need to enable the -tarball jobs to run on
pre-release and release zuul pipes for all neutron-*aas projects.

Change-Id: If9ce653c61d8bdadeec29d368207013a29f9e010
Merge "Generate tarballs for neutron-*aas on tags"