Make grenade-multinode-dvr job voting again
Make grenade-multinode-dvr job voting again

This job was set to be non-voting and was removed from
gate queue in [1]
It looks that patch [2] which was merged to stable/rocky
recently fixed this issue and this job is working fine again,
so lets make it voting and gating again.

[1] https://review.openstack.org/#/c/602097/
[2] https://review.openstack.org/#/c/595490/

Change-Id: Ied3b7c439056134388b16742448cd1da7ece04cf
Related-Bug: #1791989

mahak/neutron,openstack/neutron,noironetworks/neutron,noironetworks/neutron,mahak/neutron,openstack/neutron,mahak/neutron,openstack/neutron