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/services/audiopolicy/AudioPolicyService.h b/services/audiopolicy/AudioPolicyService.h
index 97236e3..0044e7a 100644
--- a/services/audiopolicy/AudioPolicyService.h
+++ b/services/audiopolicy/AudioPolicyService.h
@@ -168,6 +168,12 @@
 
     virtual void registerClient(const sp<IAudioPolicyServiceClient>& client);
 
+    virtual status_t acquireSoundTriggerSession(audio_session_t *session,
+                                           audio_io_handle_t *ioHandle,
+                                           audio_devices_t *device);
+
+    virtual status_t releaseSoundTriggerSession(audio_session_t session);
+
             status_t doStopOutput(audio_io_handle_t output,
                                   audio_stream_type_t stream,
                                   int session = 0);