The Bills and Ed Oliver have an agreement in place to keep the defensive tackle in Buffalo through the 2027 season, a league source confirmed to The Athletic on Saturday. Here’s what you need to know: The new deal is a 4-year, $68 million extension, including $45 million guaranteed, per a report from ESPN. Oliver has been with the Bills since 2019 and had one year remaining from his previous deal. Though the veteran missed three games at the beginning of last season due to an ankle injury, he finished the year with three pass breakups, one forced fumble and…