The inactivity probe interval of the OpenFlow  connection
to the OpenvSwitch integration bridge, in seconds. If the
value is zero, it disables the connection keepalive  fea‐
ture.

If  the  value  is  nonzero,  then it will be forced to a
value of at least 5s.

The value is set to 60 seconds by default as described in
"OVN issues in the field".

https://www.openvswitch.org/support/ovscon2019/day1/1436-OVSCON-Nouman.pdf
https://www.ovn.org/support/dist-docs/ovn-controller.8.html

Change-Id: I7066c3a8b33b482774f310c45142ac2936a5c405