The OpenStack Integration Test Suite (Tempest) doesn't use oslo.policy
library.
oslo.policy is not used in codebase and not set in requirements.txt:
https://github.com/openstack/tempest/blob/master/requirements.txt#L14

All policy.json related stuff must be removed.

Change-Id: I0d8ee710979a7eebba1e8fc176450e4c0bcbe757