Revert "Deprecate the adaptive level controller"

This reverts commit 6f37ed78d99daa36e964ff0a65b205f0916d9949.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Deprecate the adaptive level controller
> 
> Level control handled by default-on AGC.
> 
> Bug: none
> Change-Id: I405daeceece12c896d41156b649fcfd556726f77
> Reviewed-on: https://webrtc-review.googlesource.com/59682
> Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
> Reviewed-by: Alex Loiko <aleloi@webrtc.org>
> Commit-Queue: Sam Zackrisson <saza@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#22305}

TBR=solenberg@webrtc.org,saza@webrtc.org,aleloi@webrtc.org

Change-Id: Ic52f41fcbebfd2291a51b17ac788313e1ceef163
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: none
Reviewed-on: https://webrtc-review.googlesource.com/60240
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Commit-Queue: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22308}
diff --git a/api/audio_options.h b/api/audio_options.h
index 8d2880b..d62e1f8 100644
--- a/api/audio_options.h
+++ b/api/audio_options.h
@@ -43,6 +43,7 @@
     SetFrom(&delay_agnostic_aec, change.delay_agnostic_aec);
     SetFrom(&experimental_ns, change.experimental_ns);
     SetFrom(&intelligibility_enhancer, change.intelligibility_enhancer);
+    SetFrom(&level_control, change.level_control);
     SetFrom(&residual_echo_detector, change.residual_echo_detector);
     SetFrom(&tx_agc_target_dbov, change.tx_agc_target_dbov);
     SetFrom(&tx_agc_digital_compression_gain,
@@ -51,6 +52,8 @@
     SetFrom(&combined_audio_video_bwe, change.combined_audio_video_bwe);
     SetFrom(&audio_network_adaptor, change.audio_network_adaptor);
     SetFrom(&audio_network_adaptor_config, change.audio_network_adaptor_config);
+    SetFrom(&level_control_initial_peak_level_dbfs,
+            change.level_control_initial_peak_level_dbfs);
   }
 
   bool operator==(const AudioOptions& o) const {
@@ -73,6 +76,7 @@
            delay_agnostic_aec == o.delay_agnostic_aec &&
            experimental_ns == o.experimental_ns &&
            intelligibility_enhancer == o.intelligibility_enhancer &&
+           level_control == o.level_control &&
            residual_echo_detector == o.residual_echo_detector &&
            tx_agc_target_dbov == o.tx_agc_target_dbov &&
            tx_agc_digital_compression_gain ==
@@ -80,7 +84,9 @@
            tx_agc_limiter == o.tx_agc_limiter &&
            combined_audio_video_bwe == o.combined_audio_video_bwe &&
            audio_network_adaptor == o.audio_network_adaptor &&
-           audio_network_adaptor_config == o.audio_network_adaptor_config;
+           audio_network_adaptor_config == o.audio_network_adaptor_config &&
+           level_control_initial_peak_level_dbfs ==
+               o.level_control_initial_peak_level_dbfs;
   }
   bool operator!=(const AudioOptions& o) const { return !(*this == o); }
 
@@ -107,6 +113,9 @@
     ost << ToStringIfSet("delay_agnostic_aec", delay_agnostic_aec);
     ost << ToStringIfSet("experimental_ns", experimental_ns);
     ost << ToStringIfSet("intelligibility_enhancer", intelligibility_enhancer);
+    ost << ToStringIfSet("level_control", level_control);
+    ost << ToStringIfSet("level_control_initial_peak_level_dbfs",
+                         level_control_initial_peak_level_dbfs);
     ost << ToStringIfSet("residual_echo_detector", residual_echo_detector);
     ost << ToStringIfSet("tx_agc_target_dbov", tx_agc_target_dbov);
     ost << ToStringIfSet("tx_agc_digital_compression_gain",
@@ -152,6 +161,9 @@
   rtc::Optional<bool> delay_agnostic_aec;
   rtc::Optional<bool> experimental_ns;
   rtc::Optional<bool> intelligibility_enhancer;
+  rtc::Optional<bool> level_control;
+  // Specifies an optional initialization value for the level controller.
+  rtc::Optional<float> level_control_initial_peak_level_dbfs;
   // Note that tx_agc_* only applies to non-experimental AGC.
   rtc::Optional<bool> residual_echo_detector;
   rtc::Optional<uint16_t> tx_agc_target_dbov;