Precreated ports are never deleted by nova,
thus heat must delete the ports that it creates
that are internal ports.
This is important when baremetal is used via
ironic where the MAC address of the port must
match the physical node. Neutron does not
permit duplicate MAC addresses, hence ports
can't be orphaned.
Change-Id: I965abefbb10c22a635c35e3a44d227045f33885c
Story: #1766763
Task: #18791