MediaPlayer2: remove MediaPlayer2Engine

Test: MediaPlayer2 plays
Bug: 63934228
Change-Id: I2459082bf6bbe2384ed94901b1f8f28559345888
diff --git a/media/libmediaplayer2/Android.bp b/media/libmediaplayer2/Android.bp
index 17fa01c..1fa8789 100644
--- a/media/libmediaplayer2/Android.bp
+++ b/media/libmediaplayer2/Android.bp
@@ -9,7 +9,7 @@
 
     srcs: [
         "JAudioTrack.cpp",
-        "MediaPlayer2Manager.cpp",
+        "MediaPlayer2AudioOutput.cpp",
         "mediaplayer2.cpp",
     ],