Candy is indeed uncommon here, but not unheard of. You'll find it on confectionary packaging to describe the contents. There's also a chain of stores in London (elsewhere now?) called Cyber Candy that sell exotic (OK so mostly american) candy.
So it is in some use, but not that common.
Personally I object to anyone that tries to trademark a single word of our shared language. They shouldn't be able to fence bits off like that, they should have to make up their own word if they want it trademarked.
Good example for me with Cyber Candy, I've walked by one countless times but didn't think of it.
I'll make a U-turn here and say that I agree with you about using made up words, but for a different reason. I'd probably rather see random non-word brands like PreBarpTzoh, than keep having to remember region specific names for trademark reasons. Lynx/Axe is the example that immediately springs to mind, a future Candy Mush Tiger and <insert non-EU name> could be another.
So it is in some use, but not that common.
Personally I object to anyone that tries to trademark a single word of our shared language. They shouldn't be able to fence bits off like that, they should have to make up their own word if they want it trademarked.