Merge "Use zuul firewall rules in gate"

.zuul.yaml

@@ -71,6 +71,8 @@
       - ^doc/.*
     vars:
       scenario: aio
+    roles:
+        - zuul: openstack-infra/zuul-jobs
 
 - job:
     name: kolla-ansible-centos-source

tests/pre.yml

@@ -29,10 +29,5 @@
       hostname:
         name: "{{ inventory_hostname }}"
       become: true
-
-# TODO(inc0): we're dropping iptables rules but in fact we should create
-# linuxbridge-managed tunnels for control and dataplane
-
-    - name: Drop iptables rules
-      command: "iptables -F"
-      become: true
+  roles:
+    - multi-node-firewall