Git history indicates that when Nova runs on metal hosts its
address was identified via the management bridge and an IP lookup.
When the dynamic-address-fact was added this link was broken
and metal hosts have been using the fallback of ansible_host
defined in dynamic-address-fact
Note that originally the 'management_bridge' host var was relied
upon, but this change pulls this bridge from the
'container_networks.container_address.bridge'
Change-Id: I9aaca445d135b574753722d6b8de28e4f99c427b
fc1b6f3bf6