Samsung Group’s billionaire scion, Jay Y. Lee, has been sentenced to two years and six months in prison over bribery charges, concluding a trial that brought down a South Korean president and inflamed public outrage over the cozy relationship between government and business. The case -- and another being tried separately -- center on whether Lee and Samsung used illegal means to help him take control of the company founded by his grandfather. The Jan. 18 ruling creates a vacuum atop the world’s