[Canvas] Fixes Storybook for DatasourceComponent is crashing. (#110180)

* Added mock for `es_service`.

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/canvas/storybook/__mocks__/es_service.ts

@@ -0,0 +1,10 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+export const getDefaultIndex = () => {
+  return Promise.resolve('Demonstration index');
+};

x-pack/plugins/canvas/storybook/main.ts

@@ -56,6 +56,10 @@ const canvasWebpack = {
   resolve: {
     alias: {
       'src/plugins': resolve(KIBANA_ROOT, 'src/plugins'),
+      '../../lib/es_service': resolve(
+        KIBANA_ROOT,
+        'x-pack/plugins/canvas/storybook/__mocks__/es_service.ts'
+      ),
     },
   },
 };