Firebase Integration Fix for Android App

I need an experienced developer to fix and validate Firebase login for an existing Android Studio project.

Key Tasks:
- Fix or validate Firebase login for both student and admin
- Properly connect Firebase for both panels
- Resolve any Gradle or dependency errors
- Build a working APK
- Deliver updated source code and APK

Requirements:
- Expertise in Firebase and Android Studio
- Proficiency in Kotlin and Java

I will provide:
- Full source code (ZIP)
- Firebase `google-services.json` file
- Database key structure

Please ensure you have relevant experience before applying.