setKeyboardProtection method
iOS only: keeps the on-screen keyboard out of captures.
The keyboard is a private system window, so it survives whole-window protection and regions alike. iOS can nest it in a capture-excluded canvas, which is what this does; platforms where the keyboard belongs to another app leave it as a no-op.
Implementation
Future<void> setKeyboardProtection({required bool enabled}) =>
throw UnsupportedError('setKeyboardProtection() has not been implemented.');