planning: proto: add approach stage to traffic_light_unprotected_left_turn scenario
planning: proto: add approach stage to traffic_light_unprotected_left_turn scenario

xiaoxq/apollo,jinghaomiao/apollo,xiaoxq/apollo,jinghaomiao/apollo,ApolloAuto/apollo,ycool/apollo,ApolloAuto/apollo,ycool/apollo,ApolloAuto/apollo,ApolloAuto/apollo,ApolloAuto/apollo,jinghaomiao/apollo,jinghaomiao/apollo,jinghaomiao/apollo,ycool/apollo,jinghaomiao/apollo,xiaoxq/apollo,ycool/apollo,ycool/apollo,ycool/apollo,xiaoxq/apollo,xiaoxq/apollo,xiaoxq/apollo,ApolloAuto/apollo