Fixes missing firewall rules for neutron_ovs_dpdk_agent service

Fixes missing firewall rules for neutron_ovs_dpdk_agent service

Firewall config was being inherited by the dpdk service, however
since the firewall service name was the parent (neutron_ovs_agent)
and technically that service was not enabled - the rules were never
applied.  This modifies the service name as it is inherited using
map_replace.

Closes-Bug: 1674689

Change-Id: I6676205b8fc1fd578cb2435ad97fe577a9e81d95
Signed-off-by: Tim Rozet <trozet@redhat.com>
(cherry picked from commit 48a38a19347a18d4d35fb22de82136359aae5cb7)