Ability to show screens on top of native modals

[brentvatne]

A react-navigation user mentioned that they use stack navigator to show some content on top of the app when the user backgrounds it in order to obscure the content and require the user to enter some verification code to re-enter the app. If you have a native modal dialog, eg: share sheet or alert, it will be visible on top of the stack screen. There should be a way to display some content above all native views in the app.