Well, I guess it might have moved from how it was once. But today, it is with the stress on the first syllable. And I never heard of it with the second, except when my friends were teasing me with it. And I know that lots of names which used to have their stress on the second moved to the first because it's just easier to say while calling. At least I think that's why it is. When real people are called
Chava it's KHAH-vah, and with
Adam and
Chava it's ah-DAM and khah-VAH. (And Adams I know are AH-dam, too.) It's strange. I never thought of that.