Support JSON output in external router CLI, make router obj immutable

Change-Id: I6c76d9aafd64c1af7c3e28b42beabc268f824b88
diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/UpdateExternalPeerRouterCommand.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/UpdateExternalPeerRouterCommand.java
index 5667fa8..c4090e0 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/UpdateExternalPeerRouterCommand.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/UpdateExternalPeerRouterCommand.java
@@ -62,7 +62,7 @@
             print(NO_ELEMENT);
             return;
         } else if (service.externalPeerRouters().stream()
-                .noneMatch(router -> router.externalPeerRouterIp().toString().equals(ipAddress))) {
+                .noneMatch(router -> router.ipAddress().toString().equals(ipAddress))) {
             print(NO_ELEMENT);
             return;
         }
@@ -86,9 +86,9 @@
         List<ExternalPeerRouter> routers = Lists.newArrayList(service.externalPeerRouters());
 
         for (ExternalPeerRouter router: routers) {
-            print(FORMAT, router.externalPeerRouterIp(),
-                    router.externalPeerRouterMac().toString(),
-                    router.externalPeerRouterVlanId());
+            print(FORMAT, router.ipAddress(),
+                    router.macAddress().toString(),
+                    router.vlanId());
         }
     }
 }