A digital sign above a highway alerts drivers to an Amber Alert. (Photo by Getty Images)WASHINGTON — U.S. House Rep. Rudy Yakym is pursuing changes to the nation’s Amber Alert notification system after a 17-year-old girl from his home state of Indiana went missing and was later found dead. The Republican has introduced legislation named for the victim in the case, Hailey Buzbee of Fishers, Indiana. It would allow police to issue Amber Alerts, wh…