The tl;dr, is when the allocation owner support was added,
it was done so to try and use the same exception
being raised for two distinct cases. An invalid request,
and a mismatch. The reality is, we should be raising them
separately because there are two different cases we need
to guard against.
This was discovered when changing Ironic's default RBAC
policy enforcement so that the legacy policy is no longer
enabled, which meant the default path on the owner logic was
thus triggered, resulting in the failure and need to fix it.
Closes-Bug: #2048698
Change-Id: I0feefc273a2d18e7812139f59df3f43aba7d7936
c901b15f6c