Make max target input level for input controller -12dB

Launching the experiment "Increased maximum target" for
InputVolumeController: UMA on chrome showed that input level of APM is
roughly 1dBfs while output level remain unchanged and number of analog
gain change is reduced.

Bug: webrtc:457791164
Change-Id: Ic2a5befededfdfd309c7b5e817cdd18b1a1c9d9c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/457140
Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
Commit-Queue: Gustaf Ullberg <gustaf@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#47163}

modules/audio_processing/agc2/input_volume_controller.cc

diff --git a/modules/audio_processing/agc2/input_volume_controller.cc b/modules/audio_processing/agc2/input_volume_controller.cc
index 34acde7..ea78a67 100644
--- a/modules/audio_processing/agc2/input_volume_controller.cc
+++ b/modules/audio_processing/agc2/input_volume_controller.cc
@@ -133,19 +133,6 @@
 
   return rms_error_db;
 }
-
-int GetTargetRangeMaxDbfs(const InputVolumeController::Config& config,
-                          const FieldTrialsView& field_trials) {
-  if (field_trials.IsEnabled("WebRTC-Agc2MaxSpeechLevelExperimental")) {
-    RTC_LOG(LS_INFO) << "AGC2 input volume controller using experimental "
-                        "maximum speech level";
-    return config.target_range_experimental_max_dbfs;
-  } else {
-    RTC_LOG(LS_INFO)
-        << "AGC2 input volume controller using default maximum speech level";
-    return config.target_range_max_dbfs;
-  }
-}
 }  // namespace
 
 MonoInputVolumeController::MonoInputVolumeController(
@@ -388,7 +375,7 @@
       frames_since_clipped_(config.clipped_wait_frames),
       clipping_rate_log_counter_(0),
       clipping_rate_log_(0.0f),
-      target_range_max_dbfs_(GetTargetRangeMaxDbfs(config, field_trials)),
+      target_range_max_dbfs_(config.target_range_max_dbfs),
       target_range_min_dbfs_(config.target_range_min_dbfs),
       channel_controllers_(num_capture_channels) {
   RTC_LOG(LS_INFO)

modules/audio_processing/agc2/input_volume_controller.h

diff --git a/modules/audio_processing/agc2/input_volume_controller.h b/modules/audio_processing/agc2/input_volume_controller.h
index dbb9f7f..ab7f125 100644
--- a/modules/audio_processing/agc2/input_volume_controller.h
+++ b/modules/audio_processing/agc2/input_volume_controller.h
@@ -56,8 +56,7 @@
     // adjustments are done based on the speech level. For speech levels below
     // and above the range, the targets `target_range_min_dbfs` and
     // `target_range_max_dbfs` are used, respectively.
-    int target_range_max_dbfs = -30;
-    int target_range_experimental_max_dbfs = -12;
+    int target_range_max_dbfs = -12;
     int target_range_min_dbfs = -50;
     // Number of wait frames between the recommended input volume updates.
     int update_input_volume_wait_frames = 100;