systemd: Fix rootfs transaction error when PACKAGECONFIG has polkit

systemd: Fix rootfs transaction error when PACKAGECONFIG has polkit

The systemd 234 added some files to the polkit directory and the
directory the files live in must be owned by the polkitd user, else
you will receive the following error when the rootfs is being
assembled:

Error: Transaction check error:
  file /usr/share/polkit-1/rules.d conflicts between attempted installs of polkit-0.113-r0.15.core2_64 and systemd-1:234-r0.0.core2_64

The fix similar to other packages such as libvirt where the user must
exist and the directory must be created with the proper attributes.

(From OE-Core rev: e2e36bb83355208aaf5a399107b4a99e62a708d3)

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>