By Andy Silvester Omar Gutierrez was born to be in the hospitality business: he grew up in Vegas, after all. Now he’s the co-chief executive officer of the Sushi Samba Group, the operator of the City’s original hype spot at the top of the Heron Tower. He tells City A.M. how he’s staying ahead of the competition If imitation is the sincerest form of flattery, Omar Gutierrez must feel like he’s drowning in compliments. When Sushi Samba opened, it was the only place to go after work – for lunch, for post-work cocktails, for late-night partying. Now it’s surrounded by other hotspots offering a sim…