It looks like a decision is finally moving forward on a long-awaited and controversial rule affecting the roughly 1.3 million customers in California who have installed rooftop solar panels on their homes and businesses. The California Public Utilities Commission said in a notice Friday it will hear oral arguments from parties who have battled one another over potential changes to NEM, or Net Energy Metering — the rules that determine the size of the credits customers receive on their utility bills when their rooftop solar systems generate more energy than they consume. The remote hearing is s…