Here's the breakdown.
If the Bills and Chargers both finish 9-7 then the Chargers are in over the Bills. But if the Bills, Chargers AND Titans finish 9-7 then the Bills own the tiebreaker over the Chargers.
The Titans finishing 9-7 is better for the Bills -but- one of those losses has to be to the Jaguars because of the intra-conference record tiebreaker. So the Titans beating the Rams is a good thing for the Bills. A win over the Rams does nothing to change the fact that they have to lose to the Jaguars next week.
Edit: Unfortunately they just lost so there goes that.