Value Statement

Ensure the issue title clearly reflects the value of this user story to the
intended persona. (Explain the "WHY")

transferred from github https://github.com/stolostron/backlog/issues/19410

ManagedClusterImageRegistry is an ACM feature for addons to support per cluster image registry settings.

As an ACM user, I would expect all shipped addons (here is managed-serviceaccount) to support per cluster image registry configuration.

Definition of Done for Engineering Story Owner (Checklist)

• user can use ManagedClusterImageRegistry to config per cluster image registry settings for managed-serviceaccount agent.

Development Complete

• The code is complete.
• Functionality is working.
• Any required downstream Docker file changes are made.

Tests Automated

• [x] Unit/function tests have been automated and incorporated into the
  build.
• [x] 100% automated unit/function test coverage for new or changed APIs.

Secure Design

• [x] Security has been assessed and incorporated into your threat model.

Multidisciplinary Teams Readiness

• [x] Create an informative documentation issue using the [Customer
  Portal_doc_issue template](
  https://github.com/stolostron/backlog/issues/new?assignees=&labels=squad%3Adoc&template=doc_issue.md&title=),
  and ensure doc acceptance criteria is met. Link the development issue to
  the doc issue.
• [x] Provide input to the QE team, and ensure QE acceptance criteria
  (established between story owner and QE focal) are met.

Support Readiness

• [x] The must-gather script has been updated.