Fix Typescript typings in react-native-flipper (#3209)
Fix Typescript typings in react-native-flipper (#3209)

Summary:
The implementation of react-native-flipper [makes runtime assertions](https://github.com/facebook/flipper/blob/main/react-native/react-native-flipper/index.js#L20) about some variables but those type requirements [aren't properly reflected in the Typescript type defs](https://github.com/facebook/flipper/blob/main/react-native/react-native-flipper/index.d.ts#L45).

## Changelog

Corrected Typescript type defs in react-native-flipper

Pull Request resolved: https://github.com/facebook/flipper/pull/3209

Test Plan:
(No runtime effect)
In vscode, the typings now properly restrict the arguments to `FlipperResponder.success`,  `FlipperResponder.error`, and  `FlipperConnection.send`

Reviewed By: antonk52

Differential Revision: D33307792

Pulled By: mweststrate

fbshipit-source-id: da3bf7fcacdf3718dc9a625e4229f3c8ecd7ac93

facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper