Remove deprecated allow_tenant_isolation option

allow_tenant_isolation option of auth and compute groups has been
deprecated over 3 years since I78a4884e980ef7d0103639cb3792a54c69fb7761.
So we have spended much enough time for removing them, this patch does.

Change-Id: I0b0a5e16a5e3785579f95f75fa149b311d918e8c
4 files changed