HTML5 Video support

Hello. What about HTML5 video support?

Tried to open [this simple HTML page with video](https://github.com/indapublic/html5-video-test/blob/master/index.html) (page is available on https://infallible-knuth-964fc1.netlify.com) but see an only black screen. No messages or errors in the debug console.

`react-native-webview` is correctly displaying this page.

Thanks

