Implemented button to change dates for an event to reflect the academic quarter

app/src/main/java/com/denizk0461/studip/viewmodel/CanteenViewModel.kt

@@ -70,7 +70,7 @@ class CanteenViewModel(app: Application) : AppViewModel(app) {
      * This value determines whether the user wants to have allergens marked.
      */
     val preferenceAllergen: Boolean
-        get() = repo.getBooleanPreference(SettingsPreferences.ALLERGEN)
+        get() = repo.getBooleanPreference(SettingsPreferences.ALLERGEN, defaultValue = true)
 
     var preferenceCanteen: Int
         get() = repo.getIntPreference(SettingsPreferences.CANTEEN)

app/src/main/java/com/denizk0461/studip/viewmodel/SettingsViewModel.kt

@@ -60,7 +60,7 @@ class SettingsViewModel(app: Application) : AppViewModel(app) {
      * This value determines whether the user wants to have allergens marked.
      */
     var preferenceAllergen: Boolean
-        get() = repo.getBooleanPreference(SettingsPreferences.ALLERGEN)
+        get() = repo.getBooleanPreference(SettingsPreferences.ALLERGEN, defaultValue = true)
         set(newValue) { repo.setPreference(SettingsPreferences.ALLERGEN, newValue) }
 
     /**