Fixed copy/paste issue

packages/devtools_app/lib/src/screens/debugger/controls.dart

diff --git a/packages/devtools_app/lib/src/screens/debugger/controls.dart b/packages/devtools_app/lib/src/screens/debugger/controls.dart
index 0ec2a24..539e63f 100644
--- a/packages/devtools_app/lib/src/screens/debugger/controls.dart
+++ b/packages/devtools_app/lib/src/screens/debugger/controls.dart
@@ -112,7 +112,8 @@
             onPressed:
                 (!resuming && !isSystemIsolate)
                     ? () => unawaited(controller.resume())
-                  
+                    : null,
+          ),
       ],
     );
   }