Summary:
`accessibilityTraits` was missing, this diff adds it.
Also there is a name mis match, in javascript it is called `accessibilityRole`.
Changelog: [Internal]
Reviewed By: JoshuaGross
Differential Revision: D18857668
fbshipit-source-id: 10656e8fb4e8c1d771a72c7f354b845e41cfc313