Fix: e2e tests failing due to :1936/metrics unaccessible.

This PR allows access to tcp/1936 ingress infra-secgrp policy,
so that e2e test do not fail looking for router metrics port
:1936/metrics

roles/openshift_openstack/templates/heat_stack.yaml.j2

@@ -418,6 +418,10 @@ resources:
           protocol: tcp
           port_range_min: 443
           port_range_max: 443
+        - direction: ingress
+          protocol: tcp
+          port_range_min: 1936
+          port_range_max: 1936
 
   cns-secgrp:
     type: OS::Neutron::SecurityGroup