[Lens] Fix inline dimension button label (#215476)

## Summary

Fix for #209696. 

<img width="368" alt="Screenshot 2025-03-21 at 1 49 14 PM"
src="https://github.com/user-attachments/assets/69052665-a194-459b-9c2a-835f4230a99b"
/>
<img width="381" alt="Screenshot 2025-03-21 at 1 49 53 PM"
src="https://github.com/user-attachments/assets/7cf6b7eb-4d1e-40fc-a28f-597634441eb1"
/>

### Checklist

Check the PR satisfies following conditions. 

Reviewers should verify this PR satisfies this list as well.

- [x] Any text added follows [EUI's writing
guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
sentence case text and includes [i18n
support](https://github.com/elastic/kibana/blob/main/src/platform/packages/shared/kbn-i18n/README.md)

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>
Co-authored-by: Marco Liberati <dej611@users.noreply.github.com>

x-pack/platform/plugins/shared/lens/public/editor_frame_service/editor_frame/config_panel/buttons/empty_dimension_button.tsx

@@ -33,6 +33,7 @@ import {
 } from '../../../../types';
 
 interface EmptyButtonProps {
+  isInlineEditing: boolean;
   columnId: string;
   onClick: (id: string) => void;
   group: VisualizationDimensionGroupConfig;
@@ -56,12 +57,24 @@ const defaultButtonLabels = {
   ),
 };
 
-const DefaultEmptyButton = ({ columnId, group, onClick }: EmptyButtonProps) => {
+const defaultInlineButtonLabels = {
+  ariaLabel: (l: string) =>
+    i18n.translate('xpack.lens.indexPattern.addColumnAriaLabel.inline', {
+      defaultMessage: 'Add a field to {groupLabel}',
+      values: { groupLabel: l },
+    }),
+  label: (
+    <FormattedMessage id="xpack.lens.configure.emptyConfig.inline" defaultMessage="Add a field" />
+  ),
+};
+
+const DefaultEmptyButton = ({ isInlineEditing, columnId, group, onClick }: EmptyButtonProps) => {
   const { buttonAriaLabel, buttonLabel } = group.labels || {};
+  const defaultLabels = isInlineEditing ? defaultInlineButtonLabels : defaultButtonLabels;
   return (
     <EmptyDimensionButtonInner
-      label={buttonLabel || defaultButtonLabels.label}
-      ariaLabel={buttonAriaLabel || defaultButtonLabels.ariaLabel(group.groupLabel)}
+      label={buttonLabel || defaultLabels.label}
+      ariaLabel={buttonAriaLabel || defaultLabels.ariaLabel(group.groupLabel)}
       dataTestSubj="lns-empty-dimension"
       onClick={() => onClick(columnId)}
     />
@@ -98,6 +111,7 @@ export function EmptyDimensionButton({
   activeVisualization,
   order,
   target,
+  isInlineEditing,
 }: {
   order: [2, number, number, number];
   group: VisualizationDimensionGroupConfig;
@@ -116,6 +130,7 @@ export function EmptyDimensionButton({
       label: string;
     };
   };
+  isInlineEditing: boolean;
 }) {
   const [{ dragging }] = useDragDropContext();
 
@@ -177,6 +192,7 @@ export function EmptyDimensionButton({
     columnId: value.columnId,
     onClick,
     group,
+    isInlineEditing,
   };
 
   return (

x-pack/platform/plugins/shared/lens/public/editor_frame_service/editor_frame/config_panel/layer_panel.tsx

@@ -703,6 +703,7 @@ export function LayerPanel(props: LayerPanelProps) {
                         }}
                         onDrop={onDrop}
                         indexPatterns={dataViews.indexPatterns}
+                        isInlineEditing={isInlineEditing}
                       />
                     ) : null}
                   </>