Fix missing ID3 events

When I moved the id3Reader instantiation out of the while
loop (below where it is now) it was no longer guarded by
the streamTypes.get(streamType) deduping check. This brings
back an equivalent check.

library/src/main/java/com/google/android/exoplayer/extractor/ts/TsExtractor.java

@@ -52,16 +52,17 @@ public final class TsExtractor implements Extractor, SeekMap {
   private static final long MAX_PTS = 0x1FFFFFFFFL;
 
   private final ParsableByteArray tsPacketBuffer;
-  private final SparseBooleanArray streamTypes;
-  private final SparseBooleanArray allowedPassthroughStreamTypes;
-  private final SparseArray<TsPayloadReader> tsPayloadReaders; // Indexed by pid
-  private final long firstSampleTimestampUs;
   private final ParsableBitArray tsScratch;
+  private final long firstSampleTimestampUs;
+  /* package */ final SparseBooleanArray streamTypes;
+  /* package */ final SparseBooleanArray allowedPassthroughStreamTypes;
+  /* package */ final SparseArray<TsPayloadReader> tsPayloadReaders; // Indexed by pid
 
   // Accessed only by the loading thread.
   private ExtractorOutput output;
   private long timestampOffsetUs;
   private long lastPts;
+  /* package */ Id3Reader id3Reader;
 
   public TsExtractor() {
     this(0, null);
@@ -307,9 +308,11 @@ public final class TsExtractor implements Extractor, SeekMap {
       // Skip the descriptors.
       data.skipBytes(programInfoLength);
 
+      if (id3Reader == null) {
         // Setup an ID3 track regardless of whether there's a corresponding entry, in case one
         // appears intermittently during playback. See b/20261500.
-      Id3Reader id3Reader = new Id3Reader(output.track(TS_STREAM_TYPE_ID3));
+        id3Reader = new Id3Reader(output.track(TS_STREAM_TYPE_ID3));
+      }
 
       int entriesSize = sectionLength - 9 /* Size of the rest of the fields before descriptors */
           - programInfoLength - 4 /* CRC size */;