Revert of Introduced new scheme for controlling the functionality inside the audio processing module

webrtc/modules/audio_processing/level_controller/level_controller.cc

Index: webrtc/modules/audio_processing/level_controller/level_controller.cc
diff --git a/webrtc/modules/audio_processing/level_controller/level_controller.cc b/webrtc/modules/audio_processing/level_controller/level_controller.cc
index c0edeb91c50f5a472019f07eb45ce97910d9ea12..2294396607505f86511e83f12f110a8a636601bf 100644
--- a/webrtc/modules/audio_processing/level_controller/level_controller.cc
+++ b/webrtc/modules/audio_processing/level_controller/level_controller.cc
@@ -262,17 +262,4 @@
                         audio->channels_f()[0], *sample_rate_hz_, 1);
 }
 
-std::string LevelController::ToString(
-    const AudioProcessing::Config::LevelController& config) {
-  std::stringstream ss;
-  ss << "{"
-     << "enabled: " << (config.enabled ? "true" : "false") << "}";
-  return ss.str();
-}
-
-bool LevelController::Validate(
-    const AudioProcessing::Config::LevelController& config) {
-  return true;
-}
-
 }  // namespace webrtc