Allow sheet to reflect theme

Expo/react native

**Is your feature request related to a problem you're having? Please describe.**
When signing in with google when in dark mode, the sheet flashes white first and is a bit abrasive.

**Describe the solution you'd like**
I'd love for it to support the theme (if it doesn't already, I could be missing something.

**Describe alternatives you've considered**
I believe I ran into this in another app I built with SwiftUI and I was able to create a custom sheet. I'm not sure if that's possible here.

**Additional context**