I don't know what meta-ethics are held by the Christian masses—does it actually come up very often?—but Catholic doctrine tends strongly towards Thomism, which isn't divine command theorist, and Catholicism is the largest sect of Christianity. I suspect that most Catholics would be dimly aware that divine command theory isn't quite right, upon considering the issue. I don't think that my "average Catholic" friend has ever considered meta-ethics in a detailed enough way such that she could distinguish between divine command theory and some alternative meta-ethical theory. After all, in all theistic meta-ethics morality stems from God in some sense, it's just the exact way in which it does so that is contentious. The sort of distinctions that are necessary to make are I believe quite beyond the philosophical competencies of your average Christian.