In change Ib0cf5d55750f13d0499a570f14024dca551ed4d4, we stopped waiting
for vif plug events during hard reboot and start, because the behavior
of neutron plug events depended on the vif type and we couldn't rely on
the stale network info cache.
This refines the logic not to wait for vif plug events only for the
bridge vif type, instead of for all types. We also add a flag to
_create_domain_and_network to indicate that we're in the middle of a
reboot and to expect to wait for plug events for all vif types except
the bridge vif type, regardless of the vif's 'active' status.
We only query network_info from neutron at the beginning of a reboot,
before we've unplugged anything, so the majority of the time, the vifs
will be active=True. The current logic in get_neutron_events will only
expect events for vifs with 'active' status False. This adds a way to
override that if we know we've already unplugged vifs as part of a
reboot.
Related-Bug: #1744361
Change-Id: Ib08afad3822f2ca95cfeea18d7f4fc4cb407b4d6
aaf37a26d6