Optionalapp: ReactNativeFirebase.FirebaseAppOptionaloptions: AppCheckOptionsReturns synchronously for firebase-js-sdk parity; native provider setup continues in
the background. On native platforms use ReactNativeFirebaseAppCheckProvider to configure
Device Check, App Attest, Play Integrity, or debug providers. firebase-js-sdk
ReCaptchaEnterpriseProvider / ReCaptchaV3Provider are web only and have no RN equivalent.
Initializes App Check for the given Firebase app.