Enable live_migration_events in nova-ovs-hybrid-plug
Enable live_migration_events in nova-ovs-hybrid-plug

The flag was added to prevent the source host neutron agents to trigger
a vif-plugged event too early during a live migration. But actually it
can be used in a more generic sense as the code filter on migration_to
binding profile attribute.

We saw too early vif-plugged events from neutron during evacuation in
post part of the nova-ovs-hybrid-plug job. So this patch enables the
workaround flag for this job too.

Closes-Bug: #1971563
Change-Id: Ifd20ece3a4f126da16f077247c2f1e072edb7163

mahak/nova,mahak/nova,mahak/nova,openstack/nova,openstack/nova,openstack/nova