For 49 seasons, fans have cheered, jeered and tailgated around the parking lot in the communal setting of Arrowhead Stadium. Officially, that ended on Thursday, a day before the first, and only, home game of this Chiefs preseason. The cheering and tailgating won’t change. What’s changed in the stadium’s name. When the Chiefs kick off against the Minnesota Vikings Friday evening, they’ll do so at GEHA Field at Arrowhead. The stadium opened in 1972, a shared space with Royals Stadium, now Kauffman Stadium, at the revolutionary Truman Sports Complex located east of downtown Kansas City. And the C…