Remove EVENT_NEW_TIMESTAMP symbol until fully implemented

Change-Id: I8e5dda004580ee97258d8d82721edee24ec2b929
diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h
index e9f0131..54e86b9 100644
--- a/include/media/AudioTrack.h
+++ b/include/media/AudioTrack.h
@@ -59,9 +59,11 @@
                                     // voluntary invalidation by mediaserver, or mediaserver crash.
         EVENT_STREAM_END = 7,       // Sent after all the buffers queued in AF and HW are played
                                     // back (after stop is called)
+#if 0   // FIXME not yet implemented
         EVENT_NEW_TIMESTAMP = 8,    // Delivered periodically and when there's a significant change
                                     // in the mapping from frame position to presentation time.
                                     // See AudioTimestamp for the information included with event.
+#endif
     };
 
     /* Client should declare a Buffer and pass the address to obtainBuffer()