SDK / exoplayer

* AudioTagPayloadReader was strangely parsing an audioSpecificConfig
  itself, using the parsed values to build a new audioSpecificConfig,
  then passing the newly constructed instance to be parsed by
  CodecSpecificDataUtil. Unfortunately the translation was lossy ;).
* Treat Duration=0 as an unknown duration.

Issue #1137
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=112143569