This CL adds one frame (10 ms) of silence in APM output after unmuting to mask audio resulting from the turning on the processing that was deactivated during the muting. Bug: b/177830919 Change-Id: If44cfb0ef270dde839dcd3f0b98d1c91e81668dd Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/211343 Reviewed-by: Sam Zackrisson <saza@webrtc.org> Commit-Queue: Per Åhgren <peah@webrtc.org> Cr-Commit-Position: refs/heads/master@{#33454}