Add initialization data for VP9 and AV1 codec in MatroskaExtractor

Update `MatroskaExtractor` to populate the CSD information for VP9 and AV1 codecs with their codec private data.

For reference: [CodecPrivate for VP9](https://www.webmproject.org/docs/container/#vp9-codec-feature-metadata-codecprivate), [CSD for AV1](https://aomediacodec.github.io/av1-isobmff/#av1codecconfigurationbox-syntax).

PiperOrigin-RevId: 702631838

Author: Googler

libraries/extractor/src/main/java/androidx/media3/extractor/mkv/MatroskaExtractor.java

@@ -2156,9 +2156,11 @@ public void initializeOutput(ExtractorOutput output, int trackId) throws ParserE
           break;
         case CODEC_ID_VP9:
           mimeType = MimeTypes.VIDEO_VP9;
+          initializationData = codecPrivate == null ? null : ImmutableList.of(codecPrivate);
           break;
         case CODEC_ID_AV1:
           mimeType = MimeTypes.VIDEO_AV1;
+          initializationData = codecPrivate == null ? null : ImmutableList.of(codecPrivate);
           break;
         case CODEC_ID_MPEG2:
           mimeType = MimeTypes.VIDEO_MPEG2;