SDK / exoplayer

Note that we still have null timelines in ExoPlayerImplInternal.
This is deliberate; and is likely necessary to distinguish between
the no-timeline-yet and timeline-is-empty cases (we want to try
and process a pending seek for the latter, but not the former).

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=140200980