Kris Kolluri, the CEO and president of the Gateway Development Commission, is stepping down, NorthJersey.com has learned.Kolluri, who has overseen the bistate agency in charge of the $16 billion Hudson River rail tunnels project, informed the commission’s co-chairs, Alicia Glen, Balpreet Grewal-Virk and Tony Coscia, of his resignation in a letter dated July 18.“The progress…