[ML] Enable function tests for imported trained models (elastic#177407)

## Summary

Closes elastic#175443

### Checklist

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [x] [Flaky Test
Runner](https://ci-stats.kibana.dev/trigger_flaky_test_runner/1) was
used on any tests changed

(cherry picked from commit 84889d0)

x-pack/test/functional/apps/ml/short_tests/model_management/model_list.ts

@@ -449,8 +449,7 @@ export default function ({ getService }: FtrProviderContext) {
         await ml.navigation.navigateToTrainedModels();
       });
 
-      // FLAKY: https://github.com/elastic/kibana/issues/175443
-      describe.skip('with imported models', function () {
+      describe('with imported models', function () {
         before(async () => {
           await ml.navigation.navigateToTrainedModels();
         });

x-pack/test/functional/services/ml/trained_models_table.ts

@@ -582,6 +582,7 @@ export function TrainedModelsTableProvider(
       await mlCommonUI.assertLastToastHeader(
         `Deployment for "${modelId}" has been stopped successfully.`
       );
+      await mlCommonUI.waitForRefreshButtonEnabled();
     }
 
     public async openStartDeploymentModal(modelId: string) {