Fix iptables modules references in rule generation

Fix iptables modules references in rule generation

The way we were generating rules with module references
for TCP, UDP, and ICMP was not matching the output of
iptables-save so all of the counters for those rules
were being destroyed on each iptables reload.

This patch corrects the generation so it's in line with
iptables-save output. It uses the matching module name only
when a specific port number or port range is specified.
It also uses the full 'ipv6-icmp' protocol name that shows
up in the output rather than 'icmpv6'.

Closes-Bug: #1502924
Change-Id: I1bf9a85cd299a7618d29c72991612898c5437442