Added a bitexactness test for the echo control mobile in the audio processing module

BUG=webrtc:5663

Review URL: https://codereview.webrtc.org/1805373002

Cr-Original-Commit-Position: refs/heads/master@{#12069}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 105831ef4a38ac49e5e2c1ce207884da0a26c773
2 files changed