Modify release date for 2.18.1 and media3:1.0.0-beta02

Also rearranged release notes to correctly show when the changes were released.

#minor-release

PiperOrigin-RevId: 462361982
(cherry picked from commit c6e69a3)

Author: rohitjoins

RELEASENOTES.md

@@ -1,6 +1,6 @@
 # Release notes
 
-### 2.18.1 (2022-07-15)
+### 2.18.1 (2022-07-21)
 
 This release corresponds to the
 [AndroidX media3 1.0.0-beta02 release](https://github.com/androidx/media/releases/tag/1.0.0-beta02).
@@ -18,8 +18,6 @@ This release corresponds to the
         `DefaultMediaSourceFactory`, which was non-functional in some cases
         ([#116](https://github.com/androidx/media/issues/116)).
 *   Extractors:
-    *   Add support for AVI
-        ([#2092](https://github.com/google/ExoPlayer/issues/2092)).
     *   Fix parsing of H265 short term reference picture sets
         ([#10316](https://github.com/google/ExoPlayer/issues/10316)).
     *   Fix parsing of bitrates from `esds` boxes
@@ -32,8 +30,6 @@ This release corresponds to the
         playback controls menu
         ([#10298](https://github.com/google/ExoPlayer/issues/10298)).
 *   RTSP:
-    *   Add RTP reader for H263
-        ([#63](https://github.com/androidx/media/pull/63)).
     *   Add VP8 fragmented packet handling
         ([#110](https://github.com/androidx/media/pull/110)).
 *   Leanback extension:
@@ -140,6 +136,8 @@ This release corresponds to the
     *   Remove `RawCcExtractor`, which was only used to handle a Google-internal
         subtitle format.
 *   Extractors:
+    *   Add support for AVI
+        ([#2092](https://github.com/google/ExoPlayer/issues/2092)).
     *   Matroska: Parse `DiscardPadding` for Opus tracks.
     *   MP4: Parse bitrates from `esds` boxes.
     *   Ogg: Allow duplicate Opus ID and comment headers
@@ -189,6 +187,8 @@ This release corresponds to the
         of `DefaultCompositeSequenceableLoaderFactory` can be passed explicitly
         if required.
 *   RTSP:
+    *   Add RTP reader for H263
+        ([#63](https://github.com/androidx/media/pull/63)).
     *   Add RTP reader for MPEG4
         ([#35](https://github.com/androidx/media/pull/35)).
     *   Add RTP reader for HEVC