Brian Daboll already was the frontrunner to fill the Giants’ head coaching vacancy. Now he’s the first known finalist for the job. Daboll, the Buffalo Bills’ offensive coordinator, will be the first candidate to conduct a second interview with the Giants. He will interview in person on Tuesday at the team’s facility in East Rutherford, N.J., according to sources. Daboll is getting a second interview before the Giants hold a first with candidates Brian Flores, the ex-Miami Dolphins head coach, and Pat Graham, the Giants’ incumbent defensive coordinator.