(MODULES-8736) IPtables support on RHEL8

(MODULES-8736) IPtables support on RHEL8

In order to persist the nftables rules on RHEL8, we need the init scripts:
"Warning: Firewall[998 log all ipv4](provider=iptables): Unable to persist firewall rules:
Execution of '/usr/libexec/iptables/iptables.init save' returned 1:
Error: Could not execute posix command: No such file or directory - /usr/libexec/iptables/iptables.init",

Those are contained in the iptables-services package, so this patch aims
to add it into package_name for RHEL8.

Also, to make the IPtables-managed rules persistent at reboot, we need
to enable iptables (and ip6tables) service(s) like we did in previous
versions of RHEL ecosystem.