fix build

Change-Id: I9f28063edcfd7a1026ced9df58c4c2f652c03b4b
diff --git a/tests/tests/os/src/android/os/cts/MessageQueueTest.java b/tests/tests/os/src/android/os/cts/MessageQueueTest.java
index 288f5e1..8906c42 100644
--- a/tests/tests/os/src/android/os/cts/MessageQueueTest.java
+++ b/tests/tests/os/src/android/os/cts/MessageQueueTest.java
@@ -215,7 +215,12 @@
         MessageQueue queue = Looper.getMainLooper().getQueue();
         try {
             queue.addOnFileDescriptorEventListener(null, 0,
-                    new OnFileDescriptorEventListener() { });
+                    new OnFileDescriptorEventListener() {
+                @Override
+                public int onFileDescriptorEvents(FileDescriptor fd, int events) {
+                    return 0;
+                }
+            });
             fail("Expected IllegalArgumentException");
         } catch (IllegalArgumentException ex) {
             // expected