This PR:
- fixes some errors reported by `gradlew lint` and the Android Studio "Code Inspection" tool
- adds a snapshot file `lint-baseline.xml` of the remaining lint errors and warnings to be used by the linter as baseline
- adds a job for CI to run `gradlew lint` on every build
Reviewed-on: https://codeberg.org/Freeyourgadget/Gadgetbridge/pulls/3291
Reviewed-by: José Rebelo <joserebelo@noreply.codeberg.org>
Co-authored-by: Arjan Schrijver <a_gadgetbridge@anymore.nl>
Co-committed-by: Arjan Schrijver <a_gadgetbridge@anymore.nl>
