Summary:
I'm pretty sure this is supposed to be "bottom" as opposed to "top", as it's the offset from the keyboard, which is at the bottom of the screen.
Closes https://github.com/facebook/react-native/pull/11446
Differential Revision: D4339957
Pulled By: lacker
fbshipit-source-id: 62dca544a0167704d76cd972c44570f277ea63aa