LOS ANGELES—Police were searching Sunday for a gunman who shot four people after a brawl erupted outside a Los Angeles restaurant hosting a party that followed a Justin Bieber concert, authorities said. Detectives are asking witnesses to come forward to help them identify the suspect in the shooting early Saturday outside The Nice Guy restaurant. The victims’ names were not released, but NBC News reported rapper Kodak Black was among the wounded. Four men ages 60, 24, 22 and 19 were hospitalized in stable condition, LA police Officer Mike Lopez said. Videos posted on TMZ.com and on social media show Black, 24, posing for photos with a group of people outside the restaurant when the brawl broke out. Black is among several people involved in the fight before shots rang out, sending everyone running for cover. Law enforcement sources told NBC News that Black, whose legal name is Bill Kapri, …