ONOS-635 Adding ICMPv6 type and code builder for HostMonitor.

aovid duplicate call of toString.

Apply changes to FlowEntryBuilder and FlowModBuilder as well.
Fix missing break; issue.

Change-Id: I1a2e59ca943bbcc9677b9fc0cb9eb2f7cb3d7aa3
diff --git a/core/api/src/main/java/org/onosproject/net/flow/DefaultTrafficSelector.java b/core/api/src/main/java/org/onosproject/net/flow/DefaultTrafficSelector.java
index 756fdd7..e5f552d 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/DefaultTrafficSelector.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/DefaultTrafficSelector.java
@@ -194,6 +194,16 @@
         }
 
         @Override
+        public Builder matchIcmpv6Type(Byte icmpv6Type) {
+            return add(Criteria.matchIcmpv6Type(icmpv6Type));
+        }
+
+        @Override
+        public Builder matchIcmpv6Code(Byte icmpv6Code) {
+            return add(Criteria.matchIcmpv6Code(icmpv6Code));
+        }
+
+        @Override
         public Builder matchMplsLabel(Integer mplsLabel) {
             return add(Criteria.matchMplsLabel(mplsLabel));
         }