The Neutron owned Static Routes created in the OVN database are marked
with the external_ids key neutron:is_static_route. This mark will be used
by the OVN DB sync tool to distinguish the Neutron created Static Routes
from those added externally; the second ones should not be altered during
the sync process. The static route update task runs only once during the
maintenance task, and if all entries are already configured, no action is
performed.
Related-bug: #2027742
Change-Id: I4226024cb4cfd85bdf4f717d42d48150cab22442
89835e43e8