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
diff --git a/devstack/plugin.sh b/devstack/plugin.sh
index af71066..9daf285 100644
--- a/devstack/plugin.sh
+++ b/devstack/plugin.sh
@@ -105,6 +105,11 @@
        iniset $TEMPEST_CONFIG policy-feature-enabled changed_nova_policies_ussuri False
     fi
 
+    if [[ ${DEVSTACK_SERIES} == 'train' ]]; then
+       # Remove this once stable/train becomes EOL.
+       iniset $TEMPEST_CONFIG policy-feature-enabled changed_nova_policies_ussuri False
+    fi
+
     iniset $TEMPEST_CONFIG patrole rbac_test_roles $RBAC_TEST_ROLES
 }