re-re-enable lint unnecessary_const (#20103)

diff --git a/packages/flutter_tools/test/emulator_test.dart b/packages/flutter_tools/test/emulator_test.dart
index 4286019..5bdf1fd 100644
--- a/packages/flutter_tools/test/emulator_test.dart
+++ b/packages/flutter_tools/test/emulator_test.dart
@@ -193,7 +193,7 @@
       'system-images;android-27;google_apis_playstore;x86\n'
       'null\n'; // Yep, these really end with null (on dantup's machine at least)
 
-  static const ListEquality<String> _equality = const ListEquality<String>();
+  static const ListEquality<String> _equality = ListEquality<String>();
   final List<String> _existingAvds = <String>['existing-avd-1'];
 
   @override