(Bloomberg) -- High above the shimmering waters of Lake Lucerne in the Swiss Alps, one of the world’s wealthiest families convened in early September.Mukesh Ambani, India’s richest and most powerful private citizen, retreated with his wife, three grown children and their partners to the Bürgenstock resort at a key moment for their sprawling business empire, Reliance Industries Ltd.The coronavirus pandemic had gutted the global econom...