EAST RUTHERFORD, N.J. — It’s never a walk in the park for the Flyers. And why would the Stadium Series at MetLife Stadium be any different? Just because the Flyers were playing on a rink situated amidst a park setting — with benches, joggers, bicycles being pushed around, and dogs going for walks during the commercial breaks — and under the stars, that didn’t mean they wouldn’t follow their season-long trend of falling behind and trying to come back. The Flyers found themselves in an early 2-0 hole before making it 3-1, 4-2, and 5-3. But in the end, it was to no avail as they lost 6-3 to the N…