Add MP3 test asset with VBRI frame

This was hand-crafted with a 4-entry ToC by modifying
`bear-vbr-xing-header.mp3` in a hex editor.

The output difference from 117 samples to 116 samples is due to the
calculation in `VbriSeeker` assuming that the ToC includes the VBRI
frame itself, which I don't think is correct (fix is in a follow-up
change).

Issue: #1904

#cherrypick

PiperOrigin-RevId: 700254516

libraries/extractor/src/test/java/androidx/media3/extractor/mp3/Mp3ExtractorTest.java

@@ -71,6 +71,12 @@ public void mp3SampleWithInfoHeaderAndTrailingGarbage() throws Exception {
         simulationConfig);
   }
 
+  @Test
+  public void mp3SampleWithVbriHeader() throws Exception {
+    ExtractorAsserts.assertBehavior(
+        Mp3Extractor::new, "media/mp3/bear-vbr-vbri-header.mp3", simulationConfig);
+  }
+
   @Test
   public void mp3SampleWithCbrSeeker() throws Exception {
     ExtractorAsserts.assertBehavior(