Fix an analyzer warning (#9643)

diff --git a/dev/integration_tests/channels/lib/main.dart b/dev/integration_tests/channels/lib/main.dart
index 025f3e1..0042967 100644
--- a/dev/integration_tests/channels/lib/main.dart
+++ b/dev/integration_tests/channels/lib/main.dart
@@ -185,7 +185,7 @@
         floatingActionButton: new FloatingActionButton(
           key: const ValueKey<String>('step'),
           onPressed: _executeNextStep,
-          child: new Icon(Icons.navigate_next),
+          child: const Icon(Icons.navigate_next),
         ),
       ),
     );