Stabilize tst_qpauseanimationjob

This test is highly timer dependent and contains so many windows special
cases that indicate problems (when timers are not accurate or the
machine is busy).

Change-Id: Ie057d560d39300252ffb6c19b4d1446179c0e56a
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>