Kylie Jenner just launched King Kylie 2.0 ... and of course, Hailey Bieber was there, bestie mode activated, helping her celebrate the makeup drop and her new single like a boss! The makeup mogul rocked iconic flowing blue highlights -- throwback to 2015 -- flaunting her killer frame in a tiny black bra and leather pants ... while Hailey kept it chic as they hit West Hollywood Monday night. Kylie’s signature edgy glam -- the very look that launched her beauty empire -- was on full display,