Track the animationRunning flag correctly in QQuickRenderThreadSingleContextWindowManager

Track the animationRunning flag correctly in QQuickRenderThreadSingleContextWindowManager

The animationRunning value in QQuickRenderThreadSingleContextWindowManager
should always match the animation driver's running state. When the renderer
starts rendering, should check and update the animationRunning to
the current animation driver's isRunning() value after killing the
animation timer.

Change-Id: I30b55872ae1fc69b8db47ead7f1f2ee86de966c8
Reviewed-by: Andrew den Exter <andrew.den-exter@nokia.com>
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>