Added sample mime type to the track list descriptions.

The addition of sample mime types can make it easier to identify tracks in the case of mixed media (e.g. CEA-608 and CEA-708 caption tracks). This change appends the mime type to the end of the track description for all media types.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=147303187

demo/src/main/java/com/google/android/exoplayer2/demo/TrackSelectionHelper.java

@@ -301,15 +301,18 @@ import java.util.Locale;
   private static String buildTrackName(Format format) {
     String trackName;
     if (MimeTypes.isVideo(format.sampleMimeType)) {
-      trackName = joinWithSeparator(joinWithSeparator(buildResolutionString(format),
-          buildBitrateString(format)), buildTrackIdString(format));
+      trackName = joinWithSeparator(joinWithSeparator(joinWithSeparator(
+          buildResolutionString(format), buildBitrateString(format)), buildTrackIdString(format)),
+          buildSampleMimeTypeString(format));
     } else if (MimeTypes.isAudio(format.sampleMimeType)) {
-      trackName = joinWithSeparator(joinWithSeparator(joinWithSeparator(buildLanguageString(format),
-          buildAudioPropertyString(format)), buildBitrateString(format)),
-          buildTrackIdString(format));
+      trackName = joinWithSeparator(joinWithSeparator(joinWithSeparator(joinWithSeparator(
+          buildLanguageString(format), buildAudioPropertyString(format)),
+          buildBitrateString(format)), buildTrackIdString(format)),
+          buildSampleMimeTypeString(format));
     } else {
-      trackName = joinWithSeparator(joinWithSeparator(buildLanguageString(format),
-          buildBitrateString(format)), buildTrackIdString(format));
+      trackName = joinWithSeparator(joinWithSeparator(joinWithSeparator(buildLanguageString(format),
+          buildBitrateString(format)), buildTrackIdString(format)),
+          buildSampleMimeTypeString(format));
     }
     return trackName.length() == 0 ? "unknown" : trackName;
   }
@@ -342,4 +345,8 @@ import java.util.Locale;
     return format.id == null ? "" : ("id:" + format.id);
   }
 
+  private static String buildSampleMimeTypeString(Format format) {
+    return format.sampleMimeType == null ? "" : format.sampleMimeType;
+  }
+
 }