Correct android coverage; handlers are always valid.

freakboy3742 · freakboy3742 · commit c60d8f52f0fc · 2023-10-30T14:42:57.000+08:00
diff --git a/android/src/toga_android/widgets/detailedlist.py b/android/src/toga_android/widgets/detailedlist.py
@@ -85,8 +85,7 @@ def __init__(self, interface):
         self._interface = interface
 
     def onRefresh(self):
-        if self._interface.on_refresh:
-            self._interface.on_refresh()
+        self._interface.on_refresh()
 
 
 class DetailedList(Widget):
