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/core/api/src/main/java/org/onosproject/net/intent/HostToHostIntent.java b/core/api/src/main/java/org/onosproject/net/intent/HostToHostIntent.java
index 8add596..d47594a 100644
--- a/core/api/src/main/java/org/onosproject/net/intent/HostToHostIntent.java
+++ b/core/api/src/main/java/org/onosproject/net/intent/HostToHostIntent.java
@@ -50,8 +50,8 @@
      */
     public HostToHostIntent(ApplicationId appId, HostId one, HostId two) {
         this(appId, one, two,
-             DefaultTrafficSelector.builder().build(),
-             DefaultTrafficTreatment.builder().build(),
+             DefaultTrafficSelector.emptySelector(),
+             DefaultTrafficTreatment.emptyTreatment(),
              ImmutableList.of(new LinkTypeConstraint(false, Link.Type.OPTICAL)));
     }