Füge Schuljahr-Icon im Menü hinzu

app/src/main/res/drawable/colored_icon_calendar.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<bitmap
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:src="@drawable/_icon_calendar"
+    android:tint="@color/adaptiveDrawableTint" />

app/src/main/res/menu/menu_main.xml

@@ -6,7 +6,8 @@
     <item
         android:id="@+id/action_year"
         android:title="Schuljahr wechseln"
-        app:showAsAction="never"
+        app:showAsAction="ifRoom"
+        android:icon="@drawable/colored_icon_calendar"
         tools:ignore="HardcodedText" />
 
     <item