audio: Introduce read PCM from FMQ session functionality

This is required for audio input direction HAL session support.

Bug:
Tag: #feature
Test: vts-tradefed run vts -m VtsHalBluetoothAudioV2_1TargetTest
Sponsor: jpawlowski@
Change-Id: I3cd25f4af0c5c16074b17dd128de95dd53978379
diff --git a/bluetooth/audio/utils/session/BluetoothAudioSession.h b/bluetooth/audio/utils/session/BluetoothAudioSession.h
index 838d1cc..8d02387 100644
--- a/bluetooth/audio/utils/session/BluetoothAudioSession.h
+++ b/bluetooth/audio/utils/session/BluetoothAudioSession.h
@@ -153,6 +153,8 @@
 
   // The control function writes stream to FMQ
   size_t OutWritePcmData(const void* buffer, size_t bytes);
+  // The control function read stream from FMQ
+  size_t InReadPcmData(void* buffer, size_t bytes);
 
   static constexpr PcmParameters kInvalidPcmParameters = {
       .sampleRate = SampleRate::RATE_UNKNOWN,