Use a variable for standardizing kubectl invocation (#8329)

* Add kubectl variable

* Replace kubectl usage by kubectl variable in roles

* Remove redundant --kubeconfig on kubectl usage

* Replace unecessary shell usage with command

roles/win_nodes/kubernetes_patch/tasks/main.yml

@@ -12,9 +12,9 @@
     # Due to https://github.com/kubernetes/kubernetes/issues/58212 we cannot rely on exit code for "kubectl patch"
     - name: Check current nodeselector for kube-proxy daemonset
       command: >-
-        {{ bin_dir }}/kubectl --kubeconfig {{ kube_config_dir }}/admin.conf
+        {{ kubectl }}
         get ds kube-proxy --namespace=kube-system
-        -o jsonpath='{.spec.template.spec.nodeSelector.{{ kube_proxy_nodeselector | regex_replace('\.', '\\.') }}}'
+        -o jsonpath={.spec.template.spec.nodeSelector.{{ kube_proxy_nodeselector | regex_replace('\.', '\\.') }}}
       register: current_kube_proxy_state
       retries: 60
       delay: 5
@@ -22,8 +22,8 @@
       changed_when: false
 
     - name: Apply nodeselector patch for kube-proxy daemonset
-      shell: >-
-        {{ bin_dir }}/kubectl --kubeconfig {{ kube_config_dir }}/admin.conf
+      command: >
+        {{ kubectl }}
         patch ds kube-proxy --namespace=kube-system --type=strategic -p
         '{"spec":{"template":{"spec":{"nodeSelector":{"{{ kube_proxy_nodeselector }}":"linux"} }}}}'
       register: patch_kube_proxy_state