Fix incorrect service name on Debian in `add-rule`

On Debian, the iptables-persistent service has been renamed to
netfilter-persistent. The svc-map includes both default, ubuntu,
and debian as ubuntu will "fallback" to debian as they are considered
the same family of distro.

Change-Id: I180a580820015a60ceb2221873a38ebbb06cf953
Merge "Fix incorrect service name on Debian in `add-rule`"