In ChannelReceive, use AcmReceiver directly, not AudioCodingModule

Bug: webrtc:9801
Change-Id: I02d76bc89c363247c8dc782db316a9f87a2b93ec
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/111504
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28766}
diff --git a/modules/audio_coding/acm2/acm_receiver.h b/modules/audio_coding/acm2/acm_receiver.h
index 8d62312..8d54cf7 100644
--- a/modules/audio_coding/acm2/acm_receiver.h
+++ b/modules/audio_coding/acm2/acm_receiver.h
@@ -138,7 +138,7 @@
   // Output:
   //   - statistics           : The current network statistics.
   //
-  void GetNetworkStatistics(NetworkStatistics* statistics);
+  void GetNetworkStatistics(NetworkStatistics* statistics) const;
 
   //
   // Flushes the NetEq packet and speech buffers.