Undercloud install errors out and gives container image prepare authentication error for RHOSP 16.1

Issue

• Undercloud install errors out and gives container image prepare authentication error for RHOSP 16.1:

Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/tripleoclient/v1/tripleo_deploy.py", line 1265, in _standalone_deploy
    parsed_args)
  File "/usr/lib/python3.6/site-packages/tripleoclient/v1/tripleo_deploy.py", line 799, in _deploy_tripleo_heat_templates
    self._prepare_container_images(env, roles_data)
  File "/usr/lib/python3.6/site-packages/tripleoclient/v1/tripleo_deploy.py", line 744, in _prepare_container_images
    env, roles_data, dry_run=True)
  File "/usr/lib/python3.6/site-packages/tripleo_common/image/kolla_builder.py", line 217, in container_images_prepare_multi
    lock=lock
  File "/usr/lib/python3.6/site-packages/tripleo_common/image/kolla_builder.py", line 336, in container_images_prepare
    images, tag_from_label)
  File "/usr/lib/python3.6/site-packages/tripleo_common/image/image_uploader.py", line 927, in discover_image_tags
    discover_args):
  File "/usr/lib64/python3.6/concurrent/futures/_base.py", line 586, in result_iterator
    yield fs.pop().result()
  File "/usr/lib64/python3.6/concurrent/futures/_base.py", line 432, in result
    return self.__get_result()
  File "/usr/lib64/python3.6/concurrent/futures/_base.py", line 384, in __get_result
    raise self._exception
  File "/usr/lib64/python3.6/concurrent/futures/thread.py", line 56, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/lib/python3.6/site-packages/tripleo_common/image/image_uploader.py", line 2504, in discover_tag_from_inspect
    'container or namespace does not exist. %s' % e)
tripleo_common.image.exception.ImageUploaderException: Unable to authenticate. This may indicate missing registry credentials or the provided container or namespace does not exist. 401 Client Error: Unauthorized for url: https://registry.redhat.io/auth/realms/rhcc/protocol/redhat-docker-v2/auth?service=docker-registry&scope=repository%3Arhosp-rhel8%2Fopenstack-cron%3Apull
None
Install artifact is located at /home/stack/undercloud-install-20200629160633.tar.bzip2