Avoid global transaction in magnifier

It's not good to use the global transaction from the render thread
like this as the UI thread could also be using it from SurfaceView. Transaction
objects require external synchronization so we could be corrupting them.

Bug: 140070297
Test: Builds
Change-Id: I17b4c1417d45cc825fca380350c326ed6b3edcf6
1 file changed