SDK / exoplayer

- Increment skippedBufferCount for VPX and ADTR.
- Set maxConsecutiveDroppedOutputBufferCount count for VPX.
  Tweak its meaning to ignore skipped frames.
- Remove outputFormat/outputBuffer changed counts. These add
  limited value. Also, MediaCodec is moving toward a model where
  you don't see the output buffers changing because you dequeue
  them one at a time (like how our extension decoders work).
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=122258530