Add sound trigger control by audio policy

Audio policy:
- Added active capture indication to sound trigger service:
recognition stops if concurrent capture is not supported.
- Added generation of reserved I/O handle and session ID for
utterance capture.

Sound trigger service
- Added sound model update callback handling.
- Added service state callback
- Simplified callback shared memory allocation.

Bug: 12378680.

Change-Id: Ib0292c2733e6df90fdae480633dd9953d0016ef1
diff --git a/include/media/AudioSystem.h b/include/media/AudioSystem.h
index cf34991..f22792f 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -309,6 +309,12 @@
     /* Set audio port configuration */
     static status_t setAudioPortConfig(const struct audio_port_config *config);
 
+
+    static status_t acquireSoundTriggerSession(audio_session_t *session,
+                                           audio_io_handle_t *ioHandle,
+                                           audio_devices_t *device);
+    static status_t releaseSoundTriggerSession(audio_session_t session);
+
     // ----------------------------------------------------------------------------
 
     class AudioPortCallback : public RefBase