[F-14] Fixes issues with annotating `AppLocalizations` class in `app_localizations.dart` file.

[kwado-tech]

Description

Fixes issues with annotating AppLocalizations class in app_localizations.dart file.

Please check the following boxes

• [x] Pull Request title is consistent with the implemented feature, fix etc.
• [x] I have followed proper descriptive code style and conventions
• [x] The code is self-documenting and has no unnecessary comments. I named the functions and variables to clearly describe their purpose.
• [ ] I have added Unit Tests and coverage is 70%+
• [x] I have tested and verified this implementation and it works as expected