That's not how bias/judgment work. You can't just agree to be unbiased, though you can certainly try to be aware of your biases and to be accordingly more sensitive to situations where you may be biased.
I wonder what the impact of this is. So many people blindly click "Agree" when presented with legalese - will this be any different? Will anyone really click the button that admits they are biased? Will anyone change their conditioned behavior because they were nagged by a modal they saw one time and promptly dismissed?