Clarifying which receiver method to call.

Change-Id: Iaf89e1ff27e257fd25c54e189e8fcd1b10e8edfc
diff --git a/media/java/android/media/midi/MidiReceiver.java b/media/java/android/media/midi/MidiReceiver.java
index d069075..f8799d4 100644
--- a/media/java/android/media/midi/MidiReceiver.java
+++ b/media/java/android/media/midi/MidiReceiver.java
@@ -23,6 +23,10 @@
  */
 abstract public class MidiReceiver {
     /**
+     * Although public, this method should be considered a private implementation
+     * detail. Client code should call {@link #send} or {@link #sendWithTimestamp}
+     * instead.
+     *
      * Called to pass MIDI data to the receiver.
      * May fail if count exceeds {@link #getMaxMessageSize}.
      *