Detect missing mobile replay integration configuration

When `Sentry.mobileReplayIntegration()` is omitted from the React Native SDK integrations array, replay setup fails silently and the release is missing without an error or alert. Consider a way to simplify setup or flag the missing integration to the developer.

[React Native Session Replay setup documentation](<https://docs.sentry.io/platforms/react-native/session-replay/#set-up>)