Following in the footsteps of General Motors’ Cruise division, Uber is preparing to sign a deal to sell a minority stake in its own autonomous vehicle unit ahead of next month’s IPO, said a person briefed on the matter. The upshot is that Uber for two years would be able to cover the costs of a unit that burned nearly $500 million last year, or about 23% of total cash burn.  Softbank (Uber’s...