Allocations created before microversion 1.8 didn't have project_id
/ user_id consumer information. In Rocky those will be migrated
to have consumer records, but using configurable sentinel values.
As part of heal_allocations, we can detect this and heal the
allocations using the instance.project_id/user_id information.
This is something we'd need if we ever use Placement allocation
information counting quotas.
Note that we should be using Placement API version 1.28 with
consumer_generation when updating the allocations, but since
people might backport this change the usage of consumer
generations is left for a follow up patch.
Related to blueprint add-consumer-generation
Change-Id: Idba40838b7b1d5389ab308f2ea40e28911aecffa
6b6d81cf2b