Update release notes for Media3 1.6.0-rc01 release

PiperOrigin-RevId: 732964311
(cherry picked from commit 7419a81aa748ba4210471f28ada9db41c1f3aa65)

RELEASENOTES.md

@@ -1,6 +1,11 @@
 # Release notes
 
-### Unreleased changes
+## 1.6
+
+### 1.6.0-rc01 (2025-03-12)
+
+This release includes the following changes since
+[1.6.0-beta01 release](#160-beta01-2025-02-26):
 
 *   Common Library:
     *   Change `SimpleBasePlayer.State` access from protected to public to make
@@ -12,58 +17,32 @@
         ([#2133](https://github.com/androidx/media/issues/2133)).
     *   Add `lastRebufferRealtimeMs` to `LoadControl.Parameter`
         ([#2113](https://github.com/androidx/media/pull/2113))
-*   Transformer:
-*   Track Selection:
 *   Extractors:
     *   Fix issue where TS streams can get stuck on some devices
         ([#2069](https://github.com/androidx/media/issues/2069)).
-*   DataSource:
-*   Audio:
-*   Video:
 *   Text:
     *   Fix handling of multi-byte UTF-8 characters in WebVTT files using CR
         line endings ([#2167](https://github.com/androidx/media/issues/2167)).
-*   Metadata:
-*   Image:
-*   DataSource:
 *   DRM:
     *   Fix `MediaCodec$CryptoException: Operation not supported in this
         configuration` error when playing ClearKey content on API < 27 devices
         ([#1732](https://github.com/androidx/media/issues/1732)).
-*   Effect:
 *   Muxers:
     *   Fix a bug in `FragmentedMp4Muxer` that creates a lot of fragments when
         only audio track is written.
-*   IMA extension:
-*   Session:
-*   UI:
 *   Downloads:
     *   Fix bug in `CacheWriter` that leaves data sources open and cache areas
         locked in case the data source throws an `Exception` other than
         `IOException`
         ([#9760](https://github.com/google/ExoPlayer/issues/9760)).
-*   OkHttp Extension:
-*   Cronet Extension:
-*   RTMP Extension:
-*   HLS Extension:
-*   DASH Extension:
-*   Smooth Streaming Extension:
-*   RTSP Extension:
-*   Decoder Extensions (FFmpeg, VP9, AV1, etc.):
 *   MIDI extension:
     *   Plumb custom `AudioSink` and `AudioRendererEventListener` instances into
         `MidiRenderer`.
-*   Leanback extension:
 *   Cast Extension:
     *   Bump the `play-services-cast-framework` dependency to 21.5.0 to fix a
         `FLAG_MUTABLE` crash in apps targeting API 34+ on devices with Google
         Play services installed but disabled
         ([#2178](https://github.com/androidx/media/issues/2178)).
-*   Test Utilities:
-*   Demo app:
-*   Remove deprecated symbols:
-
-## 1.6
 
 ### 1.6.0-beta01 (2025-02-26)