Updated the behavior for the filter adaptation in echo canceller 3

This CL adjusts the filter adaptation behavior to better handle
reverberant environments and environments with poor SNR.

It furthermore updates the unittests to handle the reduced adaptation
speed.

Bug: webrtc:8661
Change-Id: I5f1b5a4a34b333bd6c643ed3727899d0838dbf90
Reviewed-on: https://webrtc-review.googlesource.com/34184
Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
Commit-Queue: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21323}
diff --git a/modules/audio_processing/include/audio_processing.h b/modules/audio_processing/include/audio_processing.h
index 28990b8..3b8d2c4 100644
--- a/modules/audio_processing/include/audio_processing.h
+++ b/modules/audio_processing/include/audio_processing.h
@@ -1162,12 +1162,12 @@
 
   struct Filter {
     size_t length_blocks = 12;
-    float shadow_rate = 0.5f;
-    float leakage_converged = 0.01f;
-    float leakage_diverged = 1.f / 60.f;
-    float error_floor = 0.1f;
-    float main_noise_gate = 220075344.f;
-    float shadow_noise_gate = 220075344.f;
+    float shadow_rate = 0.1f;
+    float leakage_converged = 0.005f;
+    float leakage_diverged = 0.05f;
+    float error_floor = 0.001f;
+    float main_noise_gate = 20075344.f;
+    float shadow_noise_gate = 20075344.f;
   } filter;
 
   struct Erle {