Something should be done to the basics cookbook too, otherwise `unattended-upgrades` will be deleted and added in every provision. One way to do it is to remove `unattended-upgrades` from `default[:basics][:package_mask]`, run autoupdate from basics, then in autoupdate, disable the service if `node[:autoupdate][:enable]` is `False` (default).
PS: seems like `unattended-upgrades` is the right package name, not `unattended_upgrades`.