Skip coredns image when evaluating kubeadm images (#5327)

It will be enabled correctly in downloads

Change-Id: Ief0b7aa2a8ee2ba6a6849820802f8542584b2c04
Related-story: PRODX-1171

roles/download/tasks/prep_kubeadm_images.yml

@@ -41,7 +41,7 @@
     state: file
 
 - name: prep_kubeadm_images | Generate list of required images
-  command: "{{ bin_dir }}/kubeadm config images list --config={{ kube_config_dir }}/kubeadm-images.yaml"
+  shell: "{{ bin_dir }}/kubeadm config images list --config={{ kube_config_dir }}/kubeadm-images.yaml | grep -v coredns"
   register: kubeadm_images_raw
   run_once: true
   changed_when: false