United Policy.json In Cinder

Currently, there is two policy.json files in cinder. One for cinder
code, one for unit test code. It's not convenient for the developer
and easy to miss one. So we need to improve it.

blueprint united-policy.json-in-cinder

Change-Id: I760d400dd143fb79d5813407269e04800d832a53
Merge "United Policy.json In Cinder"