Added Basic CEA-708 caption support to ExoPlayer V2, roughly equivalent to the…

Added Basic CEA-708 caption support to ExoPlayer V2, roughly equivalent to the current state of CEA-608. It's still missing window (and the associated positioning and formatting) support, emulating a 3-line rollup.

Currently this has only been tested with the RawCC container, though it should work with anything that makes use of SeiReader (i.e. MPEG2-TS) with minimal changes to SeiReader.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=134781660

library/src/main/java/com/google/android/exoplayer2/source/dash/manifest/DashManifestParser.java

@@ -654,10 +654,10 @@ public class DashManifestParser extends DefaultHandler
     } else if (MimeTypes.isVideo(containerMimeType)) {
     } else if (MimeTypes.isVideo(containerMimeType)) {
       return MimeTypes.getVideoMediaMimeType(codecs);
       return MimeTypes.getVideoMediaMimeType(codecs);
     } else if (MimeTypes.APPLICATION_RAWCC.equals(containerMimeType)) {
     } else if (MimeTypes.APPLICATION_RAWCC.equals(containerMimeType)) {
-      // We currently only support CEA-608 through RawCC
-      if (codecs != null
-          && (codecs.contains("eia608") || codecs.contains("cea608"))) {
-        return MimeTypes.APPLICATION_CEA608;
+      if (codecs != null) {
+        if (codecs.contains("eia608") || codecs.contains("cea608")) {
+          return MimeTypes.APPLICATION_CEA608;
+        }
       }
       }
       return null;
       return null;
     } else if (mimeTypeIsRawText(containerMimeType)) {
     } else if (mimeTypeIsRawText(containerMimeType)) {