Change registry for bitnami/kubectl to docker.io

The bitnami images have disappeared on quay.io. According to
https://blog.bitnami.com/2021/07/vmware-joins-docker-verified-publisher.html
docker.io/bitnami should be exempt from the pull rate limits.

Author: simu

class/defaults.yml

@@ -10,7 +10,7 @@ parameters:
         tag: v1.1.0
         pullPolicy: IfNotPresent
       kubectl:
-        registry: quay.io
+        registry: docker.io
         repository: bitnami/kubectl
         tag: 1.21.5
     helmValues:

tests/golden/defaults/resource-locker/resource-locker/10_upgrade_job.yaml

@@ -86,7 +86,7 @@ spec:
                   fieldPath: metadata.namespace
             - name: NEW_VERSION
               value: v1.1.0
-          image: quay.io/bitnami/kubectl:1.21.5
+          image: docker.io/bitnami/kubectl:1.21.5
           imagePullPolicy: IfNotPresent
           name: delete-deployment
           ports: []

tests/golden/openshift4/resource-locker/resource-locker/10_upgrade_job.yaml

@@ -86,7 +86,7 @@ spec:
                   fieldPath: metadata.namespace
             - name: NEW_VERSION
               value: v1.1.0
-          image: quay.io/bitnami/kubectl:1.21.5
+          image: docker.io/bitnami/kubectl:1.21.5
           imagePullPolicy: IfNotPresent
           name: delete-deployment
           ports: []