Allow calling of setPanelState without a handler.

Created by: r-deleon

I updated the library to 3.0 and start using the method setPanelState. The thing is I'm not able to hide the panel after created. Its always collapsed even though I set explicitly to HIDDEN.

 @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    ... 
    ...


    mSlidingPanel = (SlidingUpPanelLayout) mRootView.findViewById(R.id.sliding_layout);
    mSlidingPanel.setOverlayed(false);
    mSlidingPanel.setPanelState(SlidingUpPanelLayout.PanelState.HIDDEN);
    Log.d("panel status", mSlidingPanel.getPanelState().toString());  // always "COLLAPSED"