Summary:
With accessibility prop set to true, it is not possible to access
childern elements. This makes it impossible to test Components with
appium and releatives. This commit adds support to change accessiblity
property on Touchable elements to overcome the aforementioned issue.
Closes https://github.com/facebook/react-native/pull/8243
Differential Revision: D3462949
Pulled By: javache
fbshipit-source-id: 65ce6507a1619218ab5b527c970a74af197ef462