Unconditionally sleep for offload, if the audio buffer is full.
Previously ExoPlayer would not sleep if the expected wake-up was
in 2s. This was to prevent underrun if the wake-up was delayed.
Experiments have shown that the wakup audio buffer is far more
than 2s (around 1min). Additionally,
the metric was incorrect because it measured both,
AudioTrack + DSP.
Finally, this metric was erroneous after a gapless transition,
when the head position would reset to 0 and thus the computed
delay until next wakeup was too large.
PiperOrigin-RevId: 451383701
01412f4a57