Register oslo policy opts explicitly for check_policy_json

check_policy_json() common check need [oslo_policy].policy_file
config value and it is better to register those options explicitly
in check_policy_json() in case they are not register by services.

Currently it work as oslo.policy opts are registered via some import
in service side code path for upgradechecks which are not so safe
when these code import path change.

Change-Id: I16fcce119698c7375e4b58558fdce89e78a79a9b