Improve some UI

assets/skins/default_indicator_report_off.png

assets/skins/default_indicator_report_on.png

assets/skins/default_indicator_walk_off.png

assets/skins/default_indicator_walk_on.png

fastlane/metadata/android/en-US/changelogs/48.txt

fastlane/metadata/android/fr-FR/changelogs/48.txt

lib/ui/widgets/game/mode_indicator_report.dart

lib/ui/widgets/game/mode_indicator_walk.dart

lib/ui/widgets/game/mode_toggle.dart

lib/ui/widgets/indicators/indicator_top.dart

pubspec.yaml

resources/ui/skins/default/indicator_report_off.svg

resources/ui/skins/default/indicator_report_on.svg

resources/ui/skins/default/indicator_walk_off.svg

resources/ui/skins/default/indicator_walk_on.svg