Remove latency-based frame dropping on Android.

This logic currently prevents loopback calls on Nexus 5X when it's
slightly overloaded to maintain input framerate since encoding at ~25fps
with one framedrop results in >70ms between frames naturally.

With this change applied Nexus 5X can maintain ~25fps both in and out
without building excessive latency (>2 frames) (this is now covered by
CPU adaptation outside the codec wrapper).

BUG=
R=glaznev@webrtc.org

Review URL: https://codereview.webrtc.org/1854413004 .

Cr-Commit-Position: refs/heads/master@{#12317}