Because the support library creates its own layout manually and uses
different IDs than the list_content layout we can't use the method we
used previously (and which is actually recommended in the docs).
For instance, onAttach() with an Activitiy as first argument was deprecated
with API level 23. However, the overload with a Context as first argument
does obviously not get called on older API levels. Luckily, the classes
provided by the support library handle that for us.