Absolutely not. Scientology holds no such belief. Any suggestion otherwise is as absurd as asserting that those of the Christian faith believe themselves descended from aliens because they believe there is a Heaven.
Some of the information one finds on the Internet concerning Scientology religious beliefs is a mixture of misstatements, distortions and outright lies designed to twist Scientology theology. These scurrilous statements, issued by the “Internet fringe,” are not only patently untrue, they are intentionally designed to ridicule Scientologists and denigrate their actual religious beliefs.