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
diff --git a/modules/audio_processing/include/audio_processing.h b/modules/audio_processing/include/audio_processing.h
index de77bac..e130b83 100644
--- a/modules/audio_processing/include/audio_processing.h
+++ b/modules/audio_processing/include/audio_processing.h
@@ -279,7 +279,7 @@
           float lf = 100.f;
           float mf = 1000.f;
           float hf = 5000.f;
-          float default_len = 0.7f;
+          float default_len = 0.f;
         } ep_strength;
 
         struct Mask {