Commit bc27851617 [1] in opendev.org/openstack/tripleo-ci changed the
release filename for periodic jobs to promotion-testing-hash-*.yml [2]
instead of using e.g. train.yml for OpenStack Train based releases [3].
Due to this change, container images were not pulled from the local
image registry but from trunk.registry.rdoproject.org instead [2]. This
caused our periodic jobs to fail during container image build because
when using a local registry a different namespace prefix "openstack"
(instead of *-binary such as centos-binary) is used which is not valid
on trunk.registry.rdoproject.org.

As a workaround, we force TripleO jobs to run as check jobs, no matter
what pipeline they run in [4].

Thanks to Sandeep Yadav <sandyada@redhat.com> for discovering the root
cause of this issue and providing a workaround!

Ref.:
[1] https://opendev.org/openstack/tripleo-ci/commit/bc278516174cd1133ca910bb4978397499645a34
[2] https://github.com/openstack/tripleo-quickstart/blob/master/config/release/tripleo-ci/CentOS-8/promotion-testing-hash-train.yml#L7
[3] https://github.com/openstack/tripleo-quickstart/blob/master/config/release/tripleo-ci/CentOS-8/train.yml
[4] https://opendev.org/openstack/tripleo-ci/src/branch/master/roles/ci-common-vars/vars/main.yaml#L24

Change-Id: Ib7d8fc9e6781e43e04f0a9feee261b9f3f29e1fe