packaging: setup: Added default firewall rules for postgres

Previous implementation of the setup was opening the DB
for the external connections without handling the firewall
ports.

The new implementation adds firewall rules to open postgres
DB ports in firewalld/iptables firewalls.

This feature is later used in ovirt-dwh for providing read-only
user for external connections.

Change-Id: Ie05911e70ac6a93416182116ae04daec95f59ee7
Signed-off-by: Alex Lourie <alourie@redhat.com>