Samsung Group’s billionaire scion, Jay Y. Lee, is embroiled in two simultaneous legal disputes with South Korean prosecutors over allegations of bribery and corruption. The clashes, which date back to 2015, center on whether Lee and Samsung used illegal means to help him take control of the conglomerate founded by his grandfather. One trial related to the succession case kicks off Thursday on charges including breach of duty and violating capital market and auditing laws. Separately, a retrial o