Changing OVERLAYFS_WRITABLE_PATHS in a recipe does not trigger a rebuild of the package.

e.g. given there are the definitions
> OVERLAYFS_MOUNT_POINT[app] = "/app"
> OVERLAYFS_MOUNT_POINT[data] = "/data"
in MACHINE configuration and a recipe which uses
> OVERLAYFS_WRITABLE_PATHS[app] = "/etc/myapp"
changing the overlay to "data"
> OVERLAYFS_WRITABLE_PATHS[data] = "/etc/myapp"
does not trigger a rebuild of the package.

It seems that OVERLAYFS_WRITABLE_PATHS is not considered as a recipe dependency. Adding
> do_create_overlayfs_units[vardeps] += "OVERLAYFS_WRITABLE_PATHS"
to the recipe works around the issue.

It should be considered to add
> do_create_overlayfs_units[vardeps] += "OVERLAYFS_WRITABLE_PATHS"
to meta/classes/overlayfs.bbclass