Fix: Added missing namespace in build.gradle for compatibility with Android Gradle Plugin (AGP) 7.0+

[lucianokapluk]

Hello,

I encountered an issue when trying to build the project with the latest Android Gradle Plugin (AGP) version. The build failed due to a missing namespace declaration in the android/build.gradle file, which is required for AGP 7.0 and above.

To resolve this, I have added the appropriate namespace field to the build.gradle file based on the package specified in the AndroidManifest.xml.

Changes made: Added namespace to the android/build.gradle file to ensure compatibility with AGP 7.0+. This change does not affect other parts of the codebase and should improve compatibility with future versions of Android Studio and Gradle.