Error-out the migrations (cold and live) whenever the
anti-affinity policy is violated. This addresses
violations when multiple concurrent migrations are
requested.
Added detection on:
- prep_resize
- check_can_live_migration_destination
- pre_live_migration
The improved method of detection now locks based on group_id
and considers other migrations in-progress as well.
Closes-bug: #1821755
Change-Id: I32e6214568bb57f7613ddeba2c2c46da0320fabc
33c8af1f8c