net-ovn: Remove dependency on OVS agent unit files
net-ovn: Remove dependency on OVS agent unit files

The package just contains service/unit files for systemd. I doubt they
are used in either unittests or functional tests.  In functional tests
it just causes a version mismatch in case puddle repos are out of sync.

Also it adds openvswitch-ovn-vtep package to make tests running
successfully and removes removal of OVS.

Change-Id: I5427d3228e4bde54ed440794038e3fce5fea9a61

redhat-openstack/octario,redhat-openstack/octario