adjust declared types to work with dart 2 typing at runtime (#19007)

* adjust declared types to work with dart 2 typing at runtime

* review comments

* update packages/flutter_tools/lib/src/ios/simulators.dart
diff --git a/packages/flutter_tools/lib/src/ios/mac.dart b/packages/flutter_tools/lib/src/ios/mac.dart
index 2860303..a95f504 100644
--- a/packages/flutter_tools/lib/src/ios/mac.dart
+++ b/packages/flutter_tools/lib/src/ios/mac.dart
@@ -395,7 +395,7 @@
             '-allowProvisioningUpdates',
             '-allowProvisioningDeviceRegistration',
           ].contains(buildCommand);
-        }),
+        }).toList(),
     workingDirectory: app.appDirectory,
   ));