hi handyman, I'm new to this site. but I'd did drywall and metal studs most all my working life until 19 years ago I suffered a massive stroke, and I've mounted many, many TVs on hospital/office room walls. even if your metal studs are the simple 25 gauge studs? 2 quarter in toggle bolts will hold your TV. of course when we built the walls we put 2X10 backing in the walls, but pre-existing walls toggle bolts will hold up just fine. try to get as close to the center of the studs as you can, a good stud finder should help. remember metal studs normally aren't as wide as wood studs, meaning instead of an inch and a half wooden stud a metal one is only an inch and a quarter, maybe 3/8? can't remember. tighten the toggle bolts snugly then maybe another 1/2-3/4 turn. much more will break the paper on the drywall, broken paper is harder to fix than if it has been cut!
if the bracket is less than 16" wide its only required to be centered mounted to one stud. So center the bracket on the stud and to go the extra mile(not required) put four toggles in the corners. just that simple.