doc(e2e-node-tests): fix gcloud list images cmd

contributors/devel/sig-node/e2e-node-tests.md

@@ -96,7 +96,7 @@ provided by the default image.
 List the available test images using gcloud.
 
 ```sh
-make test-e2e-node LIST_IMAGES=true
+gcloud compute images list --project="cos-cloud" --no-standard-images --filter="name ~ 'cos-beta.*'"
 ```
 
 This will output a list of the available images for the default image project.
@@ -364,4 +364,4 @@ even if the number is zero.
    ```
    $ kubectl get pod -A
    $ kubectl describe node
-   ```
+   ```