Merge branch 'release/1.12.x' into fix/ui-tests

Corona-Warn-App/src/main/AndroidManifest.xml

...nawarnapp/contactdiary/ui/day/ContactDiaryDayViewModel.kt

...a/de/rki/coronawarnapp/ui/calendar/CalendarCalculation.kt

...ain/java/de/rki/coronawarnapp/ui/calendar/CalendarView.kt

.../backgroundpriority/SettingsBackgroundPriorityFragment.kt

...rn-App/src/main/res/layout/contact_diary_day_fragment.xml

...main/res/layout/fragment_settings_background_priority.xml

...Warn-App/src/main/res/values-de/contact_diary_strings.xml

...na-Warn-App/src/main/res/values/contact_diary_strings.xml

Corona-Warn-App/src/main/res/values/strings.xml

.../rki/coronawarnapp/ui/calendar/CalendarCalculationTest.kt