Adding @Beta to Intent API classes and interfaces

Change-Id: I02a3c1a678cb4e75b5bba9a33117a9dccb6fc0f5
diff --git a/core/api/src/main/java/org/onosproject/net/intent/IntentListener.java b/core/api/src/main/java/org/onosproject/net/intent/IntentListener.java
index c4a8367..4858c7e 100644
--- a/core/api/src/main/java/org/onosproject/net/intent/IntentListener.java
+++ b/core/api/src/main/java/org/onosproject/net/intent/IntentListener.java
@@ -15,10 +15,12 @@
  */
 package org.onosproject.net.intent;
 
+import com.google.common.annotations.Beta;
 import org.onosproject.event.EventListener;
 
 /**
  * Listener for {@link IntentEvent intent events}.
  */
+@Beta
 public interface IntentListener extends EventListener<IntentEvent> {
 }