Adding @Beta to Intent API classes and interfaces

Change-Id: I02a3c1a678cb4e75b5bba9a33117a9dccb6fc0f5
diff --git a/core/api/src/main/java/org/onosproject/net/intent/constraint/AnnotationConstraint.java b/core/api/src/main/java/org/onosproject/net/intent/constraint/AnnotationConstraint.java
index 36e6157..f5439ef 100644
--- a/core/api/src/main/java/org/onosproject/net/intent/constraint/AnnotationConstraint.java
+++ b/core/api/src/main/java/org/onosproject/net/intent/constraint/AnnotationConstraint.java
@@ -15,6 +15,7 @@
  */
 package org.onosproject.net.intent.constraint;
 
+import com.google.common.annotations.Beta;
 import com.google.common.base.MoreObjects;
 import org.onosproject.net.Link;
 import org.onosproject.net.resource.link.LinkResourceService;
@@ -26,6 +27,7 @@
 /**
  * Constraint that evaluates an arbitrary link annotated value is under the specified threshold.
  */
+@Beta
 public class AnnotationConstraint extends BooleanConstraint {
 
     private final String key;