MediaPlayer2: support start position of data source

Test: cts
Bug: 112549021
Change-Id: I4062fab27aff101223cfb3924841c8e7c3afa6ce
diff --git a/media/libmediaplayer2/nuplayer2/GenericSource2.h b/media/libmediaplayer2/nuplayer2/GenericSource2.h
index 9bc5182..3cac809 100644
--- a/media/libmediaplayer2/nuplayer2/GenericSource2.h
+++ b/media/libmediaplayer2/nuplayer2/GenericSource2.h
@@ -62,7 +62,7 @@
             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();
@@ -194,7 +194,7 @@
     void onSeek(const sp<AMessage>& msg);
     status_t doSeek(int64_t seekTimeUs, MediaPlayer2SeekMode mode);
 
-    void onPrepareAsync();
+    void onPrepareAsync(int64_t startTimeUs);
 
     void fetchTextData(
             uint32_t what, media_track_type type,