Comment 3 for bug 2030061

The previous comment can be ignored. I missed that https://opendev.org/openstack/keystone/src/branch/master/keystone/assignment/core.py#L865 mostly deals with implied roles for all of the above. The issue in the application credentials case as it stands is that this returned list is filtered after the implied roles are added, which the patch works around in a similar way to _get_oauth_roles.