This commit adds role assignment test coverage for users
who have the admin role assigned on the domain.
Subsequent patches will:
- add functionality for project readers
- add functionality for project members
- add functionality for project admins
- remove the obsolete policies from policy.v3cloudsample.json
Partial-Bug: 1750673
Change-Id: I6f2231b549650d7e92920d1a67bc41eda5ab8db0
(cherry picked from commit 25f86d4e29)