Add PlayoutVolumeChange RuntimeSetting.

Add a PlayoutVolumeChange RuntimeSetting. Trigger an echo path change when the playout volume is changed.

Bug: webrtc:10608
Change-Id: I1e736b93c1865d08c7d2582f6fe00216c1e1f72e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/135746
Reviewed-by: Per Ã…hgren <peah@webrtc.org>
Reviewed-by: Fredrik Hernqvist <fhernqvist@webrtc.org>
Commit-Queue: Fredrik Hernqvist <fhernqvist@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27913}
diff --git a/modules/audio_processing/debug.proto b/modules/audio_processing/debug.proto
index 2af7c81..0c50a65 100644
--- a/modules/audio_processing/debug.proto
+++ b/modules/audio_processing/debug.proto
@@ -84,6 +84,7 @@
   optional float capture_pre_gain = 1;
   optional float custom_render_processing_setting = 2;
   optional float capture_fixed_post_gain = 3;
+  optional int32 playout_volume_change = 4;
 }
 
 message Event {