KryoNamespace improvements

- Ignore duplicate Namespace registration
- Add friendly name for helping logging

- ONOS-4528

Change-Id: Id78f2a0f6e9715a7880875039825e294a68592a9
diff --git a/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java b/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java
index c1d25b7..4073804 100644
--- a/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java
+++ b/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java
@@ -277,7 +277,7 @@
             .register(char[].class)
             .register(String[].class)
             .register(boolean[].class)
-            .build();
+            .build("BASIC");
 
     /**
      * KryoNamespace which can serialize ON.lab misc classes.
@@ -297,7 +297,7 @@
             .register(Bandwidth.class)
             .register(Bandwidth.bps(1L).getClass())
             .register(Bandwidth.bps(1.0).getClass())
-            .build();
+            .build("MISC");
 
     /**
      * Kryo registration Id for user custom registration.
@@ -542,7 +542,7 @@
             .register(VlanCodec.class)
             .register(MplsCodec.class)
             .register(NoOpCodec.class)
-            .build();
+            .build("API");
 
 
     // not to be instantiated