Tesla Inc. must face a proposed class-action lawsuit alleging that it misled consumers about its cars’ self-driving capabilities, a fresh setback for the electric-car maker just as Chief Executive Officer Elon Musk has staked the company’s future on autonomy.Tesla has been accused of overstating in 2016 that all its upcoming cars would have the “hardware needed for full self-driving capability” and would be able to drive themselves from Los Angeles to New York City by the end of 2017....