update feature flag name

packages/horizontal-layout/src/vaadin-horizontal-layout-styles.js

@@ -33,7 +33,7 @@ export const baseStyles = css`
 // using `HasSize.setSizeFull()` and others, get additional styles so that they effectively take the remaining space in
 // the layout, rather than explicitly use 100% width/height. The respective data attributes are set by Flow's `HasSize`
 // class.
-const enableLayoutImprovements = window.Vaadin.featureFlags.layoutImprovements;
+const enableLayoutImprovements = window.Vaadin.featureFlags.layoutComponentImprovements;
 const layoutImprovementStyles = css`
   ::slotted([data-width-full]) {
     flex: 1;

packages/horizontal-layout/test/enable-layout-improvements.js

@@ -1,3 +1,3 @@
 window.Vaadin ??= {};
 window.Vaadin.featureFlags ??= {};
-window.Vaadin.featureFlags.layoutImprovements = true;
+window.Vaadin.featureFlags.layoutComponentImprovements = true;

packages/vertical-layout/src/vaadin-vertical-layout-styles.js

@@ -35,7 +35,7 @@ export const baseStyles = css`
 // using `HasSize.setSizeFull()` and others, get additional styles so that they effectively take the remaining space in
 // the layout, rather than explicitly use 100% width/height. The respective data attributes are set by Flow's `HasSize`
 // class.
-const enableLayoutImprovements = window.Vaadin.featureFlags.layoutImprovements;
+const enableLayoutImprovements = window.Vaadin.featureFlags.layoutComponentImprovements;
 const layoutImprovementStyles = css`
   ::slotted([data-height-full]) {
     flex: 1;

packages/vertical-layout/test/enable-layout-improvements.js

@@ -1,3 +1,3 @@
 window.Vaadin ??= {};
 window.Vaadin.featureFlags ??= {};
-window.Vaadin.featureFlags.layoutImprovements = true;
+window.Vaadin.featureFlags.layoutComponentImprovements = true;