CORD-831 Set visibility of public net to 'public'
         Update trusty-server-multi-nic image

Change-Id: Iba45190cf050f0811f83d69561c59190ffa31f7f
diff --git a/roles/xos-install/templates/public-net.yaml.j2 b/roles/xos-install/templates/public-net.yaml.j2
index bd12924..26573ed 100644
--- a/roles/xos-install/templates/public-net.yaml.j2
+++ b/roles/xos-install/templates/public-net.yaml.j2
@@ -20,7 +20,7 @@
     public_template:
       type: tosca.nodes.NetworkTemplate
       properties:
-          visibility: private
+          visibility: public
           translation: none
           vtn_kind: PUBLIC