41st District State Senator Don White has disclosed that he plans to introduce legislation, this week, to ensure the commonwealth honors leases allowing groups to us state parks, even if the Rendell administration makes an effort to close those recreational facilities as the budget development process unfolds.    The area lawmaker says he is troubled by indications that the Governor might try to shut down the parks as the budget battle tightens.    Senator White's planned measure would preserve the rights of any group which has a valid lease to use a state park, regardless of any administration decision to close, restrict access to or or modify services at the facility.     Senator White says he finds it disturbing that that the Governor might use park closings to advance his budget position.