Android webview does not support file upload、file download and web contents debugging by default, I make this project to show solution for this problem.
For RN v0.50.0-, RN do not allow us to extend built-in components.
So CustomWebView have to copy the code from react-native/Libraries/Components/WebView/WebView.android.js.
For RN v0.50.0 and v0.50.0+, RN allow us to "Add props for overriding native component in WebView".
So we can use the new feature to implement our CustomWebView.
As we can see, the new implemention is brief.