Process ICMP type for iptables firewall

Process ICMP type for iptables firewall

In current security group code, source_port_range_min
and source_port_range_max are used to specify icmp type
and code when security group rule protocol is icmp.
However, the code _port_arg in iptables_firewall called
by _convert_sgr_to_iptables_rules skips protocol icmp
when processing the arg. This happens to both ipv4 and
ipv6 icmp firewall rules.

This fix adds --icmp-type to iptables firewall rule when
icmp type is specified.

Closes-Bug: 1289088

Change-Id: Iebf109f246d47cffc26ab3c2cf113234a4b2cffe