Store max timestamp rather than last written timestamp per track.

This allows the MuxerWrapper to keep using trackTypeToTimeUs for
calculating the video duration but slightly changes the meaning of
its interleaving constraints.

PiperOrigin-RevId: 438780686

libraries/transformer/src/main/java/androidx/media3/transformer/MuxerWrapper.java

@@ -160,7 +160,9 @@ import java.nio.ByteBuffer;
 
 
     trackTypeToBytesWritten.put(
     trackTypeToBytesWritten.put(
         trackType, trackTypeToBytesWritten.get(trackType) + data.remaining());
         trackType, trackTypeToBytesWritten.get(trackType) + data.remaining());
-    trackTypeToTimeUs.put(trackType, presentationTimeUs);
+    if (trackTypeToTimeUs.get(trackType) < presentationTimeUs) {
+      trackTypeToTimeUs.put(trackType, presentationTimeUs);
+    }
 
 
     muxer.writeSampleData(trackIndex, data, isKeyFrame, presentationTimeUs);
     muxer.writeSampleData(trackIndex, data, isKeyFrame, presentationTimeUs);
     previousTrackType = trackType;
     previousTrackType = trackType;