Summary:
The `focusedOpacity` prop is only used inside `_opacityFocused` which is not used anywhere. This pr removes this unused code.
The code was added in https://github.com/facebook/react-native/pull/10427 but it does not appear to be used in the final version of the pr.
Closes https://github.com/facebook/react-native/pull/14984
Differential Revision: D5430611
Pulled By: shergin
fbshipit-source-id: 0bc4fdef04304eae9785caaf76ae1fb12ce6651e