Adjust domain tests for changed list_domains scoping behavior

Domain admins, members and readers are now allowed to use the
list_domains endpoint by default but the returned list will contain
their own domain only. This patch adjusts some RBAC tests to account
for this new behavior.

Depends-On: https://review.opendev.org/c/openstack/keystone/+/900028
Change-Id: I3d89dd26400d06fcf4653035267a84ca1c775afa
1 file changed