Since 3.7.0, oslo policy started the DeprecationWarning[1] if
deprecated_reason and deprecated_since param are not passed
in DeprecatedRule or they are passed in RuleDefault object.
These warnings are logged for every test which increase the
log size and sometime can full the log buffer and fail the
job.
[1] https://github.com/openstack/oslo.policy/blob/3.7.0/oslo_policy/policy.py#L1538
Change-Id: Ifa8c620fe76517b1c040af5905e6a6c1cdb4c922
7e264e1f21