HDFS-13761. Add toString Method to AclFeature Class. Contributed by Shweta.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/AclFeature.java

@@ -72,6 +72,11 @@ public class AclFeature implements INode.Feature, ReferenceCounter {
     return Arrays.equals(entries, ((AclFeature) o).entries);
   }
 
+  @Override
+  public String toString() {
+    return "AclFeature : " + Integer.toHexString(hashCode()) + " Size of entries : " + entries.length;
+  }
+
   @Override
   public int hashCode() {
     return Arrays.hashCode(entries);