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/audio_processing_impl.h b/modules/audio_processing/audio_processing_impl.h
index 47eed0a..a2b023a 100644
--- a/modules/audio_processing/audio_processing_impl.h
+++ b/modules/audio_processing/audio_processing_impl.h
@@ -398,6 +398,8 @@
     bool echo_path_gain_change;
     int prev_analog_mic_level;
     float prev_pre_amp_gain;
+    int playout_volume;
+    int prev_playout_volume;
     AudioProcessingStats stats;
   } capture_ RTC_GUARDED_BY(crit_capture_);