Summary:
On iOS, when you press down native fading components, they become
transparent instantly, but then have an animated fade in/out if you
move your finger in/out of their hit box.
On react-native currently, the touchdown fades, instead of providing
instant feedback, which doesn't feel right on iOS.
I'm less familiar with Android conventions, but it seems to use fading
components for buttons less often, instead using the ripple effect from
TouchableNativeFeedback. In either case, instant feedback seems better
for the user.
Closes https://github.com/facebook/react-native/pull/10866
Differential Revision: D4175854
Pulled By: hramos
fbshipit-source-id: d993231074e8190cf4ba7ca86dc24299f05d5d8f
fa8c536b31