[Fix gate]: Cinder policy change handling in tests

Cinder policies are made more granular and now we need
to adjust the patrole tests to handle those changed policies.

This commit introduces a new flag so that we test the old
policies in stable branches and new one in Xena onwards.

Change-Id: I4be60e3e92704f8e55d3acdb0e025078ae5b21f1
9 files changed