find_record should take a domain_id argument

This allows us to use domain['tenant_id'] rather than context.is_admin
for privilege checks.

Change-Id: Ic4724c2aed8a2bcaa3409998c7d23c5c3855f975
Remove unnecessary default criterion value

Change-Id: I5a2e8ec6bb0ca988e31c21cbd4e514f83bfd5ba0