Disable puppet on upgrade for roles not upgrading

Disable puppet on upgrade for roles not upgrading

Where the role has disabled upgrades, we need to skip both the ansible and
puppet steps.  To do this we refactor the post.j2.yaml so that it can be
included in the upgrade template with an adjusted list of roles.

Note this requires https://review.openstack.org/#/c/425220/ - this
change will be required for local testing of this patch
(run mistral-db-mange populate after updating tripleo-common
and restart the mistral services, or update your repos and re-run
openstack undercloud install).

Partially-Implements: blueprint overcloud-upgrades-per-service
Change-Id: Ie7d0fa6fef3528bd93e6cde076b964ea8de3185a