Adding @Beta to PortStatisticsService

Change-Id: I2779e7309ae42806d47fb461b35d08030225f190
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/PortStatisticsService.java b/incubator/api/src/main/java/org/onosproject/incubator/net/PortStatisticsService.java
index fc9182b..746961e 100644
--- a/incubator/api/src/main/java/org/onosproject/incubator/net/PortStatisticsService.java
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/PortStatisticsService.java
@@ -15,12 +15,14 @@
  */
 package org.onosproject.incubator.net;
 
+import com.google.common.annotations.Beta;
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.statistic.Load;
 
 /**
  * Service for obtaining statistic information about device ports.
  */
+@Beta
 public interface PortStatisticsService {
 
     /**