Decrease the default reverberation in AEC3

BUG=webrtc:8161

Review-Url: https://codereview.webrtc.org/3003423002
Cr-Original-Commit-Position: refs/heads/master@{#19519}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: a387eb48b156d8143ae983c0bc75ad3495a712d5
1 file changed