AudioTrack: fix position callback after restore

When restoring an AudioTrack, the next position callback point
should not be modified and set ahead of current buffer head.
Otherwise, as frames are dropped, the new position is never reached
and an application relying on position callbacks to reload the buffer
would be stalled.

Bug: 11868603.
Change-Id: I93b2a311642a0c89944b78bcc0482d4ceed98ae4
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index b8a89a0..7c4a990 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -1675,7 +1675,6 @@
 
     // take the frames that will be lost by track recreation into account in saved position
     size_t position = mProxy->getPosition() + mProxy->getFramesFilled();
-    mNewPosition = position + mUpdatePeriod;
     size_t bufferPosition = mStaticProxy != NULL ? mStaticProxy->getBufferPosition() : 0;
     result = createTrack_l(mStreamType,
                            mSampleRate,