MediaPlayer2: support start position of data source

Test: cts
Bug: 112549021
Change-Id: I4062fab27aff101223cfb3924841c8e7c3afa6ce
diff --git a/media/libmediaplayer2/nuplayer2/RTSPSource2.h b/media/libmediaplayer2/nuplayer2/RTSPSource2.h
index 712c3e5..e5f1716 100644
--- a/media/libmediaplayer2/nuplayer2/RTSPSource2.h
+++ b/media/libmediaplayer2/nuplayer2/RTSPSource2.h
@@ -43,7 +43,7 @@
             BufferingSettings* buffering /* nonnull */) override;
     virtual status_t setBufferingSettings(const BufferingSettings& buffering) override;
 
-    virtual void prepareAsync();
+    virtual void prepareAsync(int64_t startTimeUs);
     virtual void start();
     virtual void stop();