Add better lint to improve quality

Summary

We want to improve the code quality for the applications that Murena is developping. We want to set up some lint check in CI.

App Lounge is going to be the first app benefiting from this.

Description

The idea is to fix as many lint warning as possible on AppLounge:

1. On your local computer checkout the 6559-s-add-lint branch (https://gitlab.e.foundation/e/os/apps/-/tree/6559-s-add-lint)
2. From this branch create a new branch 6559-s-fix-lint-N
3. Execute ./gradlew lintRelease and fix as many lint warning as possible.
4. Make a MR targeting the 6559-s-add-lint branch branch
5. Contact Jonathan if there are some lint you cannot fix.