Add Patrole gate job for stable/train

Now we have stable/train branch ready for devstack
and so does for all service projects.

This commit adds the Patrole testing for stable/train
by adding new jobs running on stable/train version of
openstack.

Depends-On: https://review.opendev.org/#/c/701404/

Change-Id: I3655cf176f12685dd87c52d8e4979d8f8e000a38
2 files changed