Make default audio capabilities public + update extractor list.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117251647

library/src/main/java/com/google/android/exoplayer/audio/AudioCapabilities.java

@@ -32,9 +32,9 @@ import java.util.Arrays;
 public final class AudioCapabilities {
 
   /**
-   * Default to stereo PCM on SDK < 21 and when HDMI is unplugged.
+   * The minimum audio capabilities supported by all devices.
    */
-  private static final AudioCapabilities DEFAULT_AUDIO_CAPABILITIES =
+  public static final AudioCapabilities DEFAULT_AUDIO_CAPABILITIES =
       new AudioCapabilities(new int[] {AudioFormat.ENCODING_PCM_16BIT}, 2);
 
   /**

library/src/main/java/com/google/android/exoplayer/extractor/ExtractorSampleSource.java

@@ -51,15 +51,14 @@ import java.util.List;
  * format will be detected automatically from the following supported formats:
  *
  * <ul>
- * <li>Fragmented MP4
- * ({@link com.google.android.exoplayer.extractor.mp4.FragmentedMp4Extractor})</li>
- * <li>Unfragmented MP4, including M4A
- * ({@link com.google.android.exoplayer.extractor.mp4.Mp4Extractor})</li>
- * <li>Matroska, including WebM
- * ({@link com.google.android.exoplayer.extractor.webm.WebmExtractor})</li>
+ * <li>MP4, including M4A ({@link com.google.android.exoplayer.extractor.mp4.Mp4Extractor})</li>
+ * <li>fMP4 ({@link com.google.android.exoplayer.extractor.mp4.FragmentedMp4Extractor})</li>
+ * <li>Matroska and WebM ({@link com.google.android.exoplayer.extractor.webm.WebmExtractor})</li>
+ * <li>Ogg Vorbis ({@link com.google.android.exoplayer.extractor.ogg.OggVorbisExtractor}</li>
  * <li>MP3 ({@link com.google.android.exoplayer.extractor.mp3.Mp3Extractor})</li>
  * <li>AAC ({@link com.google.android.exoplayer.extractor.ts.AdtsExtractor})</li>
  * <li>MPEG TS ({@link com.google.android.exoplayer.extractor.ts.TsExtractor}</li>
+ * <li>MPEG PS ({@link com.google.android.exoplayer.extractor.ts.PsExtractor}</li>
  * <li>FLV ({@link com.google.android.exoplayer.extractor.flv.FlvExtractor}</li>
  * </ul>
  *