Break apart AudioCodingModule and AcmReceiver

This change makes AudioCodingModule a pure sender and AcmReceiver a pure
receiver.

The Config struct is in practice no longer used by AudioCodingModule,
so a new definition is included in AcmReceiver. The old definition
remains in AudioCodingModule while downstream clients are being
updated.

Bug: webrtc:14867
Change-Id: If0d0b4214c5aa278cf6c85c5b62c6da644de20e0
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/291533
Reviewed-by: Tomas Lundqvist <tomasl@google.com>
Commit-Queue: Henrik Lundin <henrik.lundin@webrtc.org>
Reviewed-by: Jakob Ivarsson‎ <jakobi@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39244}
diff --git a/modules/audio_coding/test/Channel.h b/modules/audio_coding/test/Channel.h
index 7a8829e..ebf4461 100644
--- a/modules/audio_coding/test/Channel.h
+++ b/modules/audio_coding/test/Channel.h
@@ -13,6 +13,7 @@
 
 #include <stdio.h>
 
+#include "modules/audio_coding/acm2/acm_receiver.h"
 #include "modules/audio_coding/include/audio_coding_module.h"
 #include "modules/include/module_common_types.h"
 #include "rtc_base/synchronization/mutex.h"
@@ -54,7 +55,7 @@
                    size_t payloadSize,
                    int64_t absolute_capture_timestamp_ms) override;
 
-  void RegisterReceiverACM(AudioCodingModule* acm);
+  void RegisterReceiverACM(acm2::AcmReceiver* acm_receiver);
 
   void ResetStats();
 
@@ -83,7 +84,7 @@
  private:
   void CalcStatistics(const RTPHeader& rtp_header, size_t payloadSize);
 
-  AudioCodingModule* _receiverACM;
+  acm2::AcmReceiver* _receiverACM;
   uint16_t _seqNo;
   // 60msec * 32 sample(max)/msec * 2 description (maybe) * 2 bytes/sample
   uint8_t _payloadData[60 * 32 * 2 * 2];