To port what has been done in instack-undercloud, we need a new service
to manage IPtables rules when we need to redirect network through the
undercloud via masquerading.
It was done in instack-undercloud via bash, it'll now be done in THT via
a service, disabled by default and that will be activated in CI when
deploying with a containerized undercloud.
Co-Authored-By: Thomas Herve <therve@redhat.com>
Depends-On: Ic9a2626e73d132c3be7ff14a1f4cdba0c16c5b53
Change-Id: I93ff9a3bebcec1bc7ee188f9ec00feafca2c5117
04b898d0c1