When news broke that Mark Walter’s insurance businesses were under federal investigation and that the Lakers and Dodgers owner might be in financial trouble, Josh Kushner sensed a business opportunity.The New York venture capitalist called former Disney Chief Executive Bob Iger — his partner in a bid for a new Las Vegas NBA franchise — wondering if they might instead snap up Los Angeles’ marquee basketball team.The two quickly agreed, Kushner contacted Walter and within 72 hours the deal was done to avoid a bidding war. And with that, the younger brother of Jared Kushner, President Trump’s son-in-law, was thrust...