Added rules menu dividers

app/src/main/java/eu/faircode/email/FragmentRules.java

@@ -41,6 +41,7 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.widget.SearchView;
 import androidx.constraintlayout.widget.Group;
+import androidx.core.view.MenuCompat;
 import androidx.fragment.app.FragmentTransaction;
 import androidx.lifecycle.Observer;
 import androidx.preference.PreferenceManager;
@@ -243,6 +244,8 @@ public class FragmentRules extends FragmentBase {
             }
         });
 
+        MenuCompat.setGroupDividerEnabled(menu, true);
+
         super.onCreateOptionsMenu(menu, inflater);
     }