Remove CodecInst pt.2

The following APIs on AudioCodingModule are deprecated with this CL:
  static int NumberOfCodecs();
  static int Codec(int, CodecInst*);
  static int Codec(const char*, CodecInst*, int, size_t);
  static int Codec(const char*, int, size_t);
  absl::optional<CodecInst> SendCodec() const;
  bool RegisterReceiveCodec(int, const SdpAudioFormat&);
  int RegisterExternalReceiveCodec(int, AudioDecoder*, int, int, const std::string&);
  int UnregisterReceiveCodec(uint8_t);
  int32_t ReceiveCodec(CodecInst*);
  absl::optional<SdpAudioFormat> ReceiveFormat();

As well as this method on RtpRtcp module:
  int32_t RegisterSendPayload(const CodecInst&);

Bug: webrtc:7626
Change-Id: I1230732136f1fe9048cf74afdeab767ca57ac9ce
Reviewed-on: https://webrtc-review.googlesource.com/c/113816
Commit-Queue: Fredrik Solenberg <solenberg@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26025}
diff --git a/audio/mock_voe_channel_proxy.h b/audio/mock_voe_channel_proxy.h
index eee25c5..33b00f9 100644
--- a/audio/mock_voe_channel_proxy.h
+++ b/audio/mock_voe_channel_proxy.h
@@ -14,6 +14,7 @@
 #include <map>
 #include <memory>
 #include <string>
+#include <utility>
 #include <vector>
 
 #include "api/test/mock_frame_encryptor.h"
@@ -52,7 +53,8 @@
   MOCK_CONST_METHOD0(GetPlayoutTimestamp, uint32_t());
   MOCK_CONST_METHOD0(GetSyncInfo, absl::optional<Syncable::Info>());
   MOCK_METHOD1(SetMinimumPlayoutDelay, void(int delay_ms));
-  MOCK_CONST_METHOD1(GetRecCodec, bool(CodecInst* codec_inst));
+  MOCK_CONST_METHOD0(GetReceiveCodec,
+                     absl::optional<std::pair<int, SdpAudioFormat>>());
   MOCK_METHOD1(SetReceiveCodecs,
                void(const std::map<int, SdpAudioFormat>& codecs));
   MOCK_CONST_METHOD0(GetSources, std::vector<RtpSource>());