Enable ovn controller to be updated before ovn-northd.
Enable ovn controller to be updated before ovn-northd.

Setting this parameter on recent enough ovn controller[1] allows the
update of ovn-controller before ovn-northd without breaking the
creation of new flows.

This is the usual pattern of an tripleo update.

[1] >= ovn2.13-20.09.0-17

Change-Id: Ibbdb9d68c5fe6483357b6cdbe63ccdf8f3e097f5
Depends-On: https://review.opendev.org/c/openstack/puppet-ovn/+/763895

openstack/puppet-tripleo,openstack/puppet-tripleo,openstack/puppet-tripleo