Clearing the daemon umask means creation sites can no longer rely on
umask 0022 to remove group/other-write bits from permissive modes.
Adjust modes for daemon-owned files that previously depended on the old
umask:
- fuse-overlayfs lower file
- goroutine stack dump file
- layer migration tar-data file
- network namespace mount file
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>