By Terry Tang ASSOCIATED PRESS PHOENIX (AP)-Years ago, skateboarding was branded as a hobby for rebels or stoners in city streets, schoolyards and back alleys. Those days are long gone. Skateboarding, which has Native Hawaiian roots connected to surfing, no longer is on the fringes. It became an Olympic sport in 2020. There are numerous amateur and professional skateboarding competitions in the U.S. And on Friday, the U.S. Postal Service is issuing stamps that laud the sport, and what Indigenous groups have brought to the skating culture. Di’Orr Greenwood, 27, an artist born and raised on the Navajo Nation in Arizona whose work is featured on the new stamps, says it’s a long way from when she was a kid and people always kicked her out of certain spots just…