Clarify comment to address some values.yaml checked, and some fetched automatically in Dockerfile

The following discussion from !45 (merged) should be addressed:

• @tkuah started a discussion:

  # Keep SSOT for the applications' values.yml. We do this for these values which
  # are too complex to keep track manually. For simple values.yml, we want to check in
  # the files so that we can review changes.
  # We should remove this once CI Managed Apps substitute non-CI managed apps.
  # Then these files should be in the cluster-applications project.