Change Text style props to the correct type

[KirillTregubov]

Both doneButtonTitleStyle and infoMessageStyle are style props to Text components, therefore their type should be StyleProp<TextStyle>. This fixes a typescript bug that would disallow you from setting Text-specific styles on these properties like fontSize and fontWeight to name a few.

Note

I noticed when going through the code that you added infoContainer, infoMessage and infoMessageStyle, but only the latter is defined in the types. I tried these out and they seem to work as inteded, if you want I can add these props to the types and README so they are discoverable to future users.