audio policy: move intializations to onFirstRef()

Bug: 17896324.

Change-Id: I3bb74f5397142ac354bd815eb362e5ddacdcb463
diff --git a/services/audiopolicy/AudioPolicyService.h b/services/audiopolicy/AudioPolicyService.h
index 2cea40b..4e68ab1 100644
--- a/services/audiopolicy/AudioPolicyService.h
+++ b/services/audiopolicy/AudioPolicyService.h
@@ -134,6 +134,9 @@
     // IBinder::DeathRecipient
     virtual     void        binderDied(const wp<IBinder>& who);
 
+    // RefBase
+    virtual     void        onFirstRef();
+
     //
     // Helpers for the struct audio_policy_service_ops implementation.
     // This is used by the audio policy manager for certain operations that