[Global Search] Add ILM keyword (#213122)

## Summary

This PR adds an `ILM` keyword to the ILM application, so searching for
the keyword in Global Search would match it.
![Screenshot 2025-03-04 at 16 23
52](https://github.com/user-attachments/assets/36b12d59-62df-41c9-be48-5e2615aad299)
Closes: #150424

x-pack/platform/plugins/private/index_lifecycle_management/public/plugin.tsx

@@ -48,6 +48,7 @@ export class IndexLifecycleManagementPlugin
         id: PLUGIN.ID,
         title: PLUGIN.TITLE,
         order: 2,
+        keywords: ['ilm'],
         mount: async ({ element, history, setBreadcrumbs }) => {
           const [coreStart, { licensing }] = await getStartServices();
           const {