Add release note and update comment

RELEASENOTES.md

@@ -19,6 +19,8 @@
     *   Add support for composition-level audio effects.
 *   Track Selection:
 *   Extractors:
+    *   Fix issue where padding was not skipped when reading odd-sized chunks
+        from WAV files ([#1117](https://github.com/androidx/media/pull/1117)).
 *   Audio:
     *   Allow renderer recovery by disabling offload if audio track fails to
         initialize in offload mode.

libraries/extractor/src/main/java/androidx/media3/extractor/wav/WavHeaderReader.java

@@ -172,8 +172,9 @@ import java.io.IOException;
     while (chunkHeader.id != chunkId) {
       Log.w(TAG, "Ignoring unknown WAV chunk: " + chunkHeader.id);
       long bytesToSkip = ChunkHeader.SIZE_IN_BYTES + chunkHeader.size;
-      // To align RIFF chunks to certain boundaries the RIFF specification includes a JUNK chunk.
-      // Its contents are to be skipped when reading.
+      // According to the RIFF specification, if a chunk's body size is odd, it's followed by a
+      // padding byte of value 0. This ensures each chunk occupies an even number of bytes in the
+      // file. The padding byte isn't included in the size field.
       if (chunkHeader.size % 2 != 0) {
         bytesToSkip++; // padding present if size is odd, skip it.
       }