Add release note for deleting deprecated DefaultAudioSink constructors

These were removed in https://github.com/androidx/media/commit/0468b5ab729a606ad380d30f8215f9dd44040508

PiperOrigin-RevId: 481587098

RELEASENOTES.md

@@ -96,6 +96,9 @@
     *   Implement `getDeviceInfo()` to be able to identify `CastPlayer` when
     *   Implement `getDeviceInfo()` to be able to identify `CastPlayer` when
         controlling playback with a `MediaController`
         controlling playback with a `MediaController`
         ([#142](https://github.com/androidx/media/issues/142)).
         ([#142](https://github.com/androidx/media/issues/142)).
+*   Remove deprecated symbols:
+    *   Remove `DefaultAudioSink` constructors, use `DefaultAudioSink.Builder`
+        instead.
 
 
 ### 1.0.0-beta02 (2022-07-21)
 ### 1.0.0-beta02 (2022-07-21)