The U.S. International Trade Commission has ruled that Apple violated a Samsung standards-essential patent, and now faces an import ban on the AT&T iPhone 4, iPhone 3GS, iPhone 3G, and the first- and second-generation 3G iPad. Apple plans to appeal the decision. “We are disappointed that the Commission has overturned an earlier ruling and we plan to appeal,” Apple spokeswoman Kristin Huguet told AllThingsD. “Today’s decision has no impact…