Introduce base personas for secure RBAC
Introduce base personas for secure RBAC

This commit adds some really basic check strings that we can re-use in
the existing policies. These checks strings implement a few of the most
common and useful personas. We're also trying to implement them across
OpenStack consistently, which will improve user experience and security.

Change-Id: Ib46402414e8ed9b63f024313500aef85f0c47a41

openstack/manila,openstack/manila