ReactNative: Add New Method to Public Repo

DELIVERABLES
A forked copy of https://github.com/react-native-webview/react-native-webview, where the WebView component has a new onShouldInterceptRequest event that can be handled in React Native. It only needs to work for Android, not other platforms.

ADDITIONAL INFORMATION
I wish to use a public repo of https://github.com/react-native-webview/react-native-webview however it is missing one key method from the Android WebView component that I need exposed: "shouldInterceptRequest".

I would like for someone to create a fork of this public repo, and add a way to supply a react native (javascript) handler for this Android function. (<WebViw onShouldInterceptRequest={myCustomFunction} />)

In Android this method expects a type of WebResourceResponse (or null). The return type for this ReactNative function will need to return all the values needed to create that response in Android (file, mimetype, encoding and headers).