A Russian Uber driver working illegally in the US was caught on camera head-butting a South Carolina CEO as he held his service dog, leaving the knocked-out rider with a brain injury, according to the victim and a new lawsuit. Charleston-based CEO Bryan Kobel, 45, canceled a ride home from a French restaurant, Maison, in April because the driver refused to take his service dog, Kobel told The Post on Thursday. Disturbing surveillance footage shows the driver — identified as Vadim Uliumdzhiev, 42 — suddenly marching over and knocking out Kobel as he holds his 17-pound golden doodle in the...