AnimationEffect schedules repaints in postPaintWindow() and performs
cleanup in preScreenPaint(). With the X11-style rendering, this doesn't
have any issues, scheduled repaints will be reset during the next
compositing cycle.

But with per screen rendering, we might hit the following case

    - Paint screen 0
    - Reset scheduled repaints
    - AnimationEffect::prePaintScreen(): update the timeline
    - AnimationEffect::postPaintScreen(): schedule a repaint

    - Paint screen 1
    - Reset scheduled repaints
    - AnimationEffect::prePaintScreen(): destroy the animation
    - AnimationEffect::postPaintScreen(): no repaint is scheduled

    - Return to the event loop

In this scenario, the repaint region scheduled by AnimationEffect will
be lost when compositing is performed on screen 1.

There is no any other way to fix this issue but maintain repaint regions
per each individual screen if per screen rendering is enabled.

BUG: 428439