Either Nick Fury being alive was leaked to the public in Winter Soldier (unlikely given what is presented in the end of the movie), or he started, maybe, having contacts with more important figures over the years, revealing he is alive, or people just told he was, maybe the Avengers did, during the years he was snapped.
My guess is the second option because, in Infinity War, we see Nick Fury out in the open in a street with Maria Hill, which implies he was ok with being in the open. As for why the Damage Control guy knew (and, most crucially, not Spider-Man), may be because Damage Control was notified on where Nick Fury was all those years, somehow. After all Damage Control has connections and affiliations with superhero actions in some form, so they probably were informed on that matter. Or maybe it is "common" knowledge that Nick Fury was in space for almost a year, but Spider-Man was confused with that sentence because he thought he was with him on Earth.