How have courts interpreted the California Land Use Act when determining whether the California Department of Justice can exercise its police power?

"We agree with this aspect of the trial court's conclusion. Land use regulations, such as the Act, involve the exercise of the state's police power (Miller v. Board of Public Works, supra, 195 Cal. 477, 486-489, 234 P. 381), and it is settled that the government may not contract away its right to exercise the police power in the future. (Citations.)" (Avoc Community Developers, Inc., v. South Coast Regional Com. (1976) 17 Cal.3d 785, 800, 132 Cal.Rptr. 386, 396, 553 P.2d 546, 556.)