Fix reentrant deadlock in GLSurfaceView.

It is possible for clients to call SurfaceView
methods e.g. setFormat from the GLSurfaceView#Renderer
drawFrame callback. In this case, SurfaceView#updatewindow
will understand that a redraw is required, and will request
it back to GLSurfaceView. Remember, we are still on the GLThread
though (from the drawFrame callback). So these methods
(requestRenderAndWait, windowSizeChanged), need to be reentrant.
Also fix a data race around mWantRenderNotification, which was
accessed out of lock.

Bug: 26770615
Change-Id: Ic66a36c886ae0b085dd456a4220f0d4f270fb016