A Jersey City man admitted Wednesday to stabbing his roommate to death nearly two years ago and could spend the next 30 years in prison, Hudson County Prosecutor Esther Suarez said. Tong Cheng, 28, pleaded guilty to one count of aggravated manslaughter in the death of Yuting Ge, a 23-year-old Stevens Institure of Technology student, in the Jersey City apartment they shared on Aug. 8, 2020. The state will recommend a 30-year sentence subject to the No Early Release Act, under which 85% of the sentence must be served. Sentencing is scheduled before Hudson County Superior Court Judge John Young J…