FolderPickerActivity: call super.onCreateOptionsMenu inside overriding method

Fixes a bug where ExtendedListFragment.onCreateOptionsMenu is not called for the child fragment

Signed-off-by: Álvaro Brey <alvaro.brey@nextcloud.com>

app/src/main/java/com/owncloud/android/ui/activity/FolderPickerActivity.kt

@@ -260,7 +260,7 @@ open class FolderPickerActivity :
     override fun onCreateOptionsMenu(menu: Menu): Boolean {
         val inflater = menuInflater
         inflater.inflate(R.menu.activity_folder_picker, menu)
-        return true
+        return super.onCreateOptionsMenu(menu)
     }
 
     override fun onOptionsItemSelected(item: MenuItem): Boolean {