As the NBA attempts to restart its season despite rising cases of COVID-19 and rising numbers of hospitalizations because of the disease, it has placed an emphasis on being able to quickly discover and track the illness in players. One device the league is planning to make available for players in Orlando, Fla., is a ring that has sensors that measure different bodily functions. The ring, produced by the company Oura, isn’t foreign to NBA circles. At least not in Los Angeles.