A 37-year-old man previously convicted of an unprovoked attack on a cellmate in Garden Grove’s jail pleaded guilty Wednesday to attacking a driver in Anaheim with a metal pole and was sentenced to six years in prison. Nikolas Robert Poole attacked a 69-year-old man in a car, who was stopped at a traffic light near Brookhurst Street and Lincoln Avenue, about 11:15 a.m. March 20, 2025, Anaheim Police Department Sgt. Matt Sutter. Poole slammed a me…