add CLI for vBNG to show IP address mappings

Change-Id: I50035a69de43fcbe374bdceacfa2d2ba8f1af130
diff --git a/apps/virtualbng/src/main/java/org/onosproject/virtualbng/VbngManager.java b/apps/virtualbng/src/main/java/org/onosproject/virtualbng/VbngManager.java
index 6b2e943..37b61a7 100644
--- a/apps/virtualbng/src/main/java/org/onosproject/virtualbng/VbngManager.java
+++ b/apps/virtualbng/src/main/java/org/onosproject/virtualbng/VbngManager.java
@@ -121,7 +121,7 @@
             log.info("Did not find an available public IP address to use.");
             return null;
         }
-        log.info("Private IP to Public IP mapping: {} --> {}",
+        log.info("[ADD] Private IP to Public IP mapping: {} --> {}",
                  privateIpAddress, publicIpAddress);
 
         // Setup paths between the host configured with private IP and