hal: native audio backward compatibility

- all changes for native audio backward
  compatibility and related
- add set parameters from UI
- enable dynamic device switching
- featurize the code
- various backend concurrency changes

Change-Id: Id0f824c4b4c033f42008a4e8868652c8f6fe5c42
diff --git a/hal/audio_hw.h b/hal/audio_hw.h
index 0fc52f4..67f5279 100644
--- a/hal/audio_hw.h
+++ b/hal/audio_hw.h
@@ -309,6 +309,8 @@
     bool bt_wb_speech_enabled;
 
     int snd_card;
+    unsigned int cur_codec_backend_samplerate;
+    unsigned int cur_codec_backend_bit_width;
     void *platform;
     unsigned int offload_usecases_state;
     void *visualizer_lib;