None of the ACC is this year. They all had one non-conference game they could play. That said, ND is playing as an ACC member this year and playing the same number of ACC games as the rest of that conference. They are also available for the championship game in the conference. So this year they really are a member in almost every respect.
I have a hard time with Notre Dame. I want them to join a conference like everyone else and not get such preferential treatment, but I also understand they have some very old an interesting rivalries they play often. USC, Navy, Stanford, Michigan, Perdue. Hard to try to keep some of those going even occasionally when playing a full conference slate.