Add Format.label to the extractor test dumps

Needed to test issue:#7247

PiperOrigin-RevId: 307016276

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeTrackOutput.java

@@ -297,6 +297,7 @@ public final class FakeTrackOutput implements TrackOutput, Dumper.Dumpable {
       addIfNonDefault(dumper, "subsampleOffsetUs", format -> format.subsampleOffsetUs);
       addIfNonDefault(dumper, "selectionFlags", format -> format.selectionFlags);
       addIfNonDefault(dumper, "language", format -> format.language);
+      addIfNonDefault(dumper, "label", format -> format.label);
       if (format.drmInitData != null) {
         dumper.add("drmInitData", format.drmInitData.hashCode());
       }