SDK / exoplayer

- The package is renamed to avoid conflicts with v1, should any
app wish to include both v1 and v2 for a period of time. This is
similar to the approach used by some other open source projects
(e.g. okhttp).
- Copyright year is updated everywhere for completeness.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126895326