AudioPolicy: callback for recording configuration change

Each AudioSession tracks start / end of recording, and sends
  a callback to AudioSystem.
AudioSystem tracks a single recording callback tracking
  input source and audio session number.

Change-Id: Ic065751d9ba013e03f2a6ad8dde02542e5465ec0
diff --git a/services/audiopolicy/AudioPolicyInterface.h b/services/audiopolicy/AudioPolicyInterface.h
index 7cf44dc..42fb9e5 100644
--- a/services/audiopolicy/AudioPolicyInterface.h
+++ b/services/audiopolicy/AudioPolicyInterface.h
@@ -332,6 +332,9 @@
     virtual audio_unique_id_t newAudioUniqueId() = 0;
 
     virtual void onDynamicPolicyMixStateUpdate(String8 regId, int32_t state) = 0;
+
+    virtual void onRecordingConfigurationUpdate(int event, audio_session_t session,
+                    audio_source_t source) = 0;
 };
 
 extern "C" AudioPolicyInterface* createAudioPolicyManager(AudioPolicyClientInterface *clientInterface);