SDK / exoplayer

As part of pausing DefaultAudioSink, its position-related fields are reset. If
the audio timestamp API was in use, this results in falling back to the
getPlaybackHeadPosition API, which (on some devices) can lead to a jump in the
reported position.

Sample the position before pausing instead of after, to avoid this jump.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=189713376