Neutron should make a subport that is already attached to a trunk ACTIVE
immediately. Unfortunately there seems to be an OVN bug causing an event
triggering this to be lost, leaving the port in DOWN state forever. This
is a disaster for Kuryr, because we can't proceed to wire the pods in
such case.
This commit attempts to workaround this by making Kuryr reattach the
ports that are in DOWN state for more than 90 seconds after they're
plugged.
Change-Id: If9a3968d68dced588614cd5521d4a111e78d435f