Fixing @Beta tags

Change-Id: I93a3be9a81a8f29f7b1ce29b66f09c9bcd31e639
diff --git a/core/api/src/main/java/org/onosproject/security/SecurityUtil.java b/core/api/src/main/java/org/onosproject/security/SecurityUtil.java
index 34b4e78..444b6bb 100644
--- a/core/api/src/main/java/org/onosproject/security/SecurityUtil.java
+++ b/core/api/src/main/java/org/onosproject/security/SecurityUtil.java
@@ -16,6 +16,7 @@
 
 package org.onosproject.security;
 
+import com.google.common.annotations.Beta;
 import org.onlab.osgi.DefaultServiceDirectory;
 import org.onlab.osgi.ServiceDirectory;
 import org.onlab.osgi.ServiceNotFoundException;
@@ -24,6 +25,7 @@
 /**
  * Utility class to aid Security-Mode ONOS.
  */
+@Beta
 public final class SecurityUtil {
 
     protected static ServiceDirectory serviceDirectory = new DefaultServiceDirectory();