Fix AVI extractor WAVE format extraction

Allow `WAVEFORMAT` (in addition to `WAVEFORMATEX`), which omits initialization
data.

Fix reading of bits per sample to use little endian byte order like the other
reads. See also the wave format docs linked from
https://learn.microsoft.com/en-us/windows/win32/directshow/avi-riff-file-reference#avi-stream-headers.

PiperOrigin-RevId: 642962893

RELEASENOTES.md

@@ -13,6 +13,7 @@
         `ExportException.codecInfo`.
 *   Track Selection:
 *   Extractors:
+    *   Fix PCM audio format extraction in AVI containers.
 *   Audio:
 *   Video:
 *   Text:

libraries/extractor/src/main/java/androidx/media3/extractor/avi/StreamFormatChunk.java

@@ -83,9 +83,9 @@ private static AviChunk parseWaveFormatEx(ParsableByteArray body) {
     int channelCount = body.readLittleEndianUnsignedShort();
     int samplesPerSecond = body.readLittleEndianInt();
     body.skipBytes(6); // averageBytesPerSecond (4 bytes), nBlockAlign (2 bytes).
-    int bitsPerSample = body.readUnsignedShort();
+    int bitsPerSample = body.readLittleEndianUnsignedShort();
     int pcmEncoding = Util.getPcmEncoding(bitsPerSample);
-    int cbSize = body.readLittleEndianUnsignedShort();
+    int cbSize = body.bytesLeft() > 0 ? body.readLittleEndianUnsignedShort() : 0;
     byte[] codecData = new byte[cbSize];
     body.readBytes(codecData, /* offset= */ 0, codecData.length);