Uber launched a long-distance carpooling option for commuters in Chengdu, China. Now that China’s leading ride-hailing company, Didi Kuaidi, has forged a partnership with Lyft, Uber is facing pressure to step up its game in the region. Though Uber has already invested about $1 billion in the Chinese market—and has seen significant growth there, with its Chinese drivers serving about 1 million rides per day—Lyft’s new alliance could hamper the company’s progress, since Didi Kuaidi…