setPanelState() does ignore any call, if a sliding animation is in progress.
This means: When calling
setPanelState(SlidingUpPanelLayout.PanelState.EXPANDED
immediately followed by
setPanelState(SlidingUpPanelLayout.PanelState.HIDDEN),
the SlidingUpPanelLayout does ignore the second call, if the animation of the first one is still running.
(At least for me) This commit fixes this.