Set state when we are actually changing the state of the layout display (#1398)

packages/devtools_app/lib/src/inspector/flutter/story_of_your_layout/flex.dart

diff --git a/packages/devtools_app/lib/src/inspector/flutter/story_of_your_layout/flex.dart b/packages/devtools_app/lib/src/inspector/flutter/story_of_your_layout/flex.dart
index 2a2a11b..45e7bad 100644
--- a/packages/devtools_app/lib/src/inspector/flutter/story_of_your_layout/flex.dart
+++ b/packages/devtools_app/lib/src/inspector/flutter/story_of_your_layout/flex.dart
@@ -478,11 +478,13 @@
             // the type is dependent on the `axis` parameter
             // if the axis is the main axis the type should be [MainAxisAlignment]
             // if the axis is the cross axis the type should be [CrossAxisAlignment]
-            if (axis == direction) {
-              properties.mainAxisAlignment = newSelection;
-            } else {
-              properties.crossAxisAlignment = newSelection;
-            }
+            setState(() {
+              if (axis == direction) {
+                properties.mainAxisAlignment = newSelection;
+              } else {
+                properties.crossAxisAlignment = newSelection;
+              }
+            });
             final service = await properties.node.inspectorService;
             final arg = properties.node.valueRef;
             await service.invokeTweakFlexProperties(
@@ -490,7 +492,6 @@
               properties.mainAxisAlignment,
               properties.crossAxisAlignment,
             );
-            setState(() {});
           },
         ),
       ),