[OVN] Updates to tools/migrate_names.txt
[OVN] Updates to tools/migrate_names.txt

Updates to tools/migrate_names.txt to correctly represent
mapping between neutron and networking-ovn for metadata
agent.

Change-Id: I52f4d20c7190490b707a08e0f7dd06ccd6f43f69

mahak/neutron,openstack/neutron,openstack/neutron,mahak/neutron,mahak/neutron,openstack/neutron