PHOTO: Henry Coleman III By TOM SHANAHAN Henry Coleman III is a Duke basketball freshmen just a few days into his first year of classwork and months from his college debut, but a campus rally confronting racial injustice and systemic racism wasn’t too big for his world awareness. He was among those who addressed the crowd that gathered near Cameron Indoor Stadium designed to also spur voter registration. Duke coach Mike Krzyzewski and assistant Nolan Smith organized the…