Fix instrumentation tests

Author: cemrich

app/src/main/java/de/christinecoenen/code/zapp/app/livestream/ui/list/ChannelListFragment.kt

@@ -53,7 +53,7 @@ class ChannelListFragment : Fragment(), MenuProvider, ListItemListener {
 		channelGridView.layoutManager = GridAutofitLayoutManager(requireContext(), 400)
 		channelGridView.adapter = gridAdapter
 
-		(requireActivity() as MainActivity).addMenuProviderToSearchBar(
+		(requireActivity() as? MainActivity)?.addMenuProviderToSearchBar(
 			this,
 			viewLifecycleOwner,
 			Lifecycle.State.RESUMED

app/src/main/java/de/christinecoenen/code/zapp/app/mediathek/ui/list/MediathekListFragment.kt

@@ -68,7 +68,7 @@ class MediathekListFragment : Fragment(),
 		binding.refreshLayout.setOnRefreshListener(this)
 		binding.refreshLayout.setColorSchemeResources(R.color.colorAccent, R.color.colorPrimary)
 
-		(requireActivity() as MainActivity).addMenuProviderToSearchBar(
+		(requireActivity() as? MainActivity)?.addMenuProviderToSearchBar(
 			this,
 			viewLifecycleOwner,
 			Lifecycle.State.RESUMED

app/src/main/java/de/christinecoenen/code/zapp/app/personal/PersonalFragment.kt

@@ -122,7 +122,7 @@ class PersonalFragment : Fragment(), MenuProvider {
 			}
 		}
 
-		(requireActivity() as MainActivity).addMenuProviderToSearchBar(
+		(requireActivity() as? MainActivity)?.addMenuProviderToSearchBar(
 			this,
 			viewLifecycleOwner,
 			Lifecycle.State.RESUMED