SDK / exoplayer

[Step 4 - Partial, of []

- The capabilities checks previously performed in VideoFormatSelectorUtil
  are now performed in MediaCodecVideoTrackRenderer. This means they'll be
  useful for non-chunk use cases (e.g. when using ExtractorSampleSource).
- Added capabilities checks for audio in MediaCodecAudioTrackRenderer. We
  didn't check audio capabilities previously.
- Added functionality to allow a TrackRenderer to indicate the extent of
  its adaptive support.

The idea here is that a TrackSelector (to be introduced) will have access to:

(a) TrackGroups from the SampleSource that indicate whether they support
adaptive playbacks and the formats of each individual track.
(b) TrackRenderers that indicate whether they support adaptive playbacks as
well as how capable they are of rendering formats of individual tracks.

This is everything that a TrackSelector needs from the player components in
order to decide how to wire things up. Note that a TrackSelector may opt to
treat FORMAT_EXCEEDS_CAPABILITIES as FORMAT_HANDLED at its own risk, if it
thinks that it (or the user) knows better. This is a request that we've seen
from third parties for better handling cases where capabilities aren't
accurately reported by the underlying platform.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=114427428