Summary:
- Add mock button if a client supports the function
- Open the dialog when clicking the button
Note:
- This is a part of this PR: https://github.com/facebook/flipper/pull/488
Reviewed By: mweststrate
Differential Revision: D20440145
fbshipit-source-id: 750099020e0b2d6ed10bb20e883f6b3be664ae79