Call new AudioTrack set/ctor

Update callers of AudioTrack to use interface-based ctors/setters
when passing nullptr.

Test: Compiles
Bug: 199156212
Change-Id: Iec95de6a811fedf016d263bd321bd1109b955ed7
diff --git a/media/libmediaplayerservice/MediaPlayerService.cpp b/media/libmediaplayerservice/MediaPlayerService.cpp
index 53e3d52..c7a7a3a 100644
--- a/media/libmediaplayerservice/MediaPlayerService.cpp
+++ b/media/libmediaplayerservice/MediaPlayerService.cpp
@@ -2217,8 +2217,7 @@
                     channelMask,
                     frameCount,
                     flags,
-                    NULL, // callback
-                    NULL, // user data
+                    nullptr, // callback
                     0, // notification frames
                     mSessionId,
                     AudioTrack::TRANSFER_DEFAULT,