update canvas a11y test to import SO not re-create index (#168944)

## Summary

Related to #161882

There is no need to re-create `.kibana` index, changing to imported
saved objects.

(cherry picked from commit a1f360e)

# Conflicts:
#	x-pack/test/accessibility/apps/canvas.ts

x-pack/test/accessibility/apps/canvas.ts

@@ -10,16 +10,22 @@ import { FtrProviderContext } from '../ftr_provider_context';
 export default function ({ getService, getPageObjects }: FtrProviderContext) {
   const a11y = getService('a11y');
   const testSubjects = getService('testSubjects');
-  const esArchiver = getService('esArchiver');
+  const kibanaServer = getService('kibanaServer');
   const retry = getService('retry');
   const { common } = getPageObjects(['common']);
 
   describe('Canvas Accessibility', () => {
     before(async () => {
-      await esArchiver.load('x-pack/test/functional/es_archives/canvas/default');
+      await kibanaServer.importExport.load(
+        'x-pack/test/functional/fixtures/kbn_archiver/canvas/default'
+      );
       await common.navigateToApp('canvas');
     });
 
+    after(async () => {
+      await kibanaServer.savedObjects.cleanStandardList();
+    });
+
     it('loads workpads', async function () {
       await retry.waitFor(
         'canvas workpads visible',