Yes, you should list your security clearance. It shouldn't hurt. If Google is involved in any projects that need a security clearance, that will help you becaus

Yes, you should list your security clearance. It shouldn't hurt. If Google is involved in any projects that need a security clearance, that will help you because it means you saved them money on needing to pay, and time in getting you cleared to work on a project. It doesn't need to be prominent. Google should be experts at searching for keywords.