Container Registry Authentication (#35048)

* Test change to docker-pull-image.yml

* Add changes to use docker-pull-image.yml

* dot

* Feedback, template syntax

* Default ServiceConnectionName

* Revert eng/common changes

* Remove ServiceConnectionName (it has a default value)

eng/pipelines/docindex.yml

@@ -27,8 +27,6 @@ jobs:
       # Pull and build the docker image.
       - template: /eng/common/pipelines/templates/steps/docker-pull-image.yml
         parameters:
-          ContainerRegistryClientId: $(azuresdkimages-cr-clientid)
-          ContainerRegistryClientSecret: $(azuresdkimages-cr-clientsecret)
           ImageId: "$(DocValidationImageId)"
       # Sync docs repo onboarding files/folders
       - template: /eng/common/pipelines/templates/steps/sparse-checkout.yml