Use MissingAnnotationEmptyState for plugins (#2824)

plugins/cloudbuild/src/components/Router.tsx

@@ -20,7 +20,7 @@ import { rootRouteRef, buildRouteRef } from '../plugin';
 import { WorkflowRunDetails } from './WorkflowRunDetails';
 import { WorkflowRunsTable } from './WorkflowRunsTable';
 import { CLOUDBUILD_ANNOTATION } from './useProjectName';
-import { WarningPanel } from '@backstage/core';
+import { MissingAnnotationEmptyState } from '@backstage/core';
 
 export const isPluginApplicableToEntity = (entity: Entity) =>
   Boolean(entity.metadata.annotations?.[CLOUDBUILD_ANNOTATION]);
@@ -28,9 +28,7 @@ export const isPluginApplicableToEntity = (entity: Entity) =>
 export const Router = ({ entity }: { entity: Entity }) =>
   // TODO(shmidt-i): move warning to a separate standardized component
   !isPluginApplicableToEntity(entity) ? (
-    <WarningPanel title="Cloudbuild plugin:">
-      <pre>{CLOUDBUILD_ANNOTATION}</pre> annotation is missing on the entity.
-    </WarningPanel>
+    <MissingAnnotationEmptyState annotation={CLOUDBUILD_ANNOTATION} />
   ) : (
     <Routes>
       <Route