Reland "Correct AEC3 multichannel functionality activation"

This is a reland of 9dda1b3a484ebeef921e419406402039f3852427

Original change's description:
> Correct AEC3 multichannel functionality activation
> 
> This CL corrects the AEC3 multichannel activation
> to also work for the case when a factory is used
> for the activation.
> 
> Bug: webrtc:10913
> Change-Id: Ic2807d8bcef759261fde14447cff30633ba248dc
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/158794
> Commit-Queue: Per Åhgren <peah@webrtc.org>
> Reviewed-by: Sam Zackrisson <saza@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#29676}

Bug: webrtc:10913
Change-Id: I1cb3d0de61ea0b299158ca85433f2442c65c196f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/158886
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Commit-Queue: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29690}
diff --git a/modules/audio_processing/audio_processing_impl.cc b/modules/audio_processing/audio_processing_impl.cc
index 4573aed..fb46e04 100644
--- a/modules/audio_processing/audio_processing_impl.cc
+++ b/modules/audio_processing/audio_processing_impl.cc
@@ -1783,8 +1783,8 @@
   if (use_echo_controller) {
     // Create and activate the echo controller.
     if (echo_control_factory_) {
-      submodules_.echo_controller =
-          echo_control_factory_->Create(proc_sample_rate_hz());
+      submodules_.echo_controller = echo_control_factory_->Create(
+          proc_sample_rate_hz(), num_reverse_channels(), num_proc_channels());
     } else {
       submodules_.echo_controller = std::make_unique<EchoCanceller3>(
           EchoCanceller3Config(), proc_sample_rate_hz(), num_reverse_channels(),