Description of problem:
After doing a stack update, below containers got stuck in restarting state:

~~~
swift_proxy
heat_api_cfn
swift_container_auditor
swift_object_expirer
swift_object_updater
swift_container_replicator
swift_account_auditor
swift_account_server
swift_object_replicator
swift_container_server
swift_rsync
swift_account_reaper
swift_account_replicator
swift_object_auditor
swift_object_server
swift_container_updater
~~~

here are the docker logs:

~~~
INFO:__main__:Copying /var/lib/kolla/config_files/src/etc/mtab to /etc/mtab
INFO:__main__:Deleting /etc/hostname
ERROR:__main__:Unexpected error:
Traceback (most recent call last):
  File "/usr/local/bin/kolla_set_configs", line 411, in main
    execute_config_strategy(config)
  File "/usr/local/bin/kolla_set_configs", line 377, in execute_config_strategy
    copy_config(config)
  File "/usr/local/bin/kolla_set_configs", line 306, in copy_config
    config_file.copy()
  File "/usr/local/bin/kolla_set_configs", line 150, in copy
    self._merge_directories(source, dest)
  File "/usr/local/bin/kolla_set_configs", line 97, in _merge_directories
    os.path.join(dest, to_copy))
  File "/usr/local/bin/kolla_set_configs", line 99, in _merge_directories
    self._copy_file(source, dest)
  File "/usr/local/bin/kolla_set_configs", line 75, in _copy_file
    self._delete_path(dest)
  File "/usr/local/bin/kolla_set_configs", line 108, in _delete_path
    os.remove(path)
OSError: [Errno 16] Device or resource busy: '/etc/hostname'
~~~


Version-Release number of selected component (if applicable):
rpm -qa | grep openstack-tripleo-heat-templates
openstack-tripleo-heat-templates-8.3.1-54.el7ost.noarch

cat /etc/rhosp-release 
Red Hat OpenStack Platform release 13.0.7 (Queens)

How reproducible:


Steps to Reproduce:
1.
2.
3.

Actual results:
container stuck in restart state.

Expected results:
No issues after deployment, the container should be in a healthy state after stack update

Additional info: