Neutron L3 module in Devstack has way to conigure access to physical
network on the node. It can put physical interface to the physical
bridge or, in case when such physical device isn't set, it creates
NAT rule in iptables.
There was missing the same operation for ML2/OVN backend as L3 agent is
not used there at all.
This patch adds the same to be done in both L3 agent and ovn_agent
modules.
Closes-Bug: #1939627
Change-Id: I9e558d1d5d3edbce9e7a025ba3c11267f1579820
b1a89eb80b