NuPlayer: determine audio mode before instantiating audio decoder.

Bug: 22460159
Change-Id: I334c6dc5e1163a462155d251eaa985ff5e3858e6
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayer.h b/media/libmediaplayerservice/nuplayer/NuPlayer.h
index 38904bc..9f4c462 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayer.h
+++ b/media/libmediaplayerservice/nuplayer/NuPlayer.h
@@ -220,6 +220,7 @@
 
     void tryOpenAudioSinkForOffload(const sp<AMessage> &format, bool hasVideo);
     void closeAudioSink();
+    void determineAudioModeChange();
 
     status_t instantiateDecoder(bool audio, sp<DecoderBase> *decoder);