This change fixes a race condition that was caused by setting the file owner,
group and mode non-atomically, after the updated files had been published.
Users who were running non-root containers, without GID 0 permissions, and
had removed read permissions from other users by setting defaultMode: 0440 or
similar, were getting intermittent permission denied errors when accessing
files on secret or configmap volumes or service account tokens on projected
volumes during update.