feat: add feature flag for layout improvements (#20930)

* feat: add feature flag for layout improvements

* improve naming

Author: sissbruecker

flow-server/src/main/java/com/vaadin/experimental/FeatureFlags.java

@@ -103,6 +103,12 @@ public class FeatureFlags implements Serializable {
             "Accessible disabled buttons", "accessibleDisabledButtons",
             "https://github.com/vaadin/web-components/issues/4585", true, null);
 
+    public static final Feature LAYOUT_COMPONENT_IMPROVEMENTS = new Feature(
+            "HorizontalLayout and VerticalLayout improvements",
+            "layoutComponentImprovements",
+            "https://github.com/vaadin/flow-components/issues/6998", true,
+            null);
+
     private List<Feature> features = new ArrayList<>();
 
     File propertiesFolder = null;
@@ -133,6 +139,7 @@ public FeatureFlags(Lookup lookup) {
         features.add(new Feature(CARD_COMPONENT));
         features.add(new Feature(REACT19));
         features.add(new Feature(ACCESSIBLE_DISABLED_BUTTONS));
+        features.add(new Feature(LAYOUT_COMPONENT_IMPROVEMENTS));
         loadProperties();
     }