Adding emptyTreatment() and emptySelector()

Note: There was a change that adds a DROP action to
a traffic treatment if there are no other actions present.
To get a traffic treatment without the drop rule, use
emptyTreatment()

Change-Id: I1f23ed5e1fa7519eb94fcafa85facbad815d5e9c
diff --git a/web/api/src/test/java/org/onosproject/codec/impl/IntentCodecTest.java b/web/api/src/test/java/org/onosproject/codec/impl/IntentCodecTest.java
index 919d25d..e4a1373 100644
--- a/web/api/src/test/java/org/onosproject/codec/impl/IntentCodecTest.java
+++ b/web/api/src/test/java/org/onosproject/codec/impl/IntentCodecTest.java
@@ -67,9 +67,9 @@
     private final HostId id2 = hid("12:34:56:78:92:ab/1");
     private final ApplicationId appId = new DefaultApplicationId(3, "test");
     final TrafficSelector emptySelector =
-            DefaultTrafficSelector.builder().build();
+            DefaultTrafficSelector.emptySelector();
     final TrafficTreatment emptyTreatment =
-            DefaultTrafficTreatment.builder().build();
+            DefaultTrafficTreatment.emptyTreatment();
     private final CodecContext context = new MockCodecContext();
 
     /**