gnomeos: Add uid/group for dbus/gdm

gnomeos/yocto/classes/gnomeos-contents.bbclass

@@ -78,11 +78,19 @@ EOF
 	ln -sf /var/run/resolv.conf ${IMAGE_ROOTFS}/etc/resolv.conf
 
 	# Override base-passwd...it has lots of crap in it we don't
-	# want, and we do want dbus.
-	cat >${IMAGE_ROOTFS}/var/passwd << EOF
+	# want, and we do want dbus/gdm etc.
+	cat >${IMAGE_ROOTFS}/etc/passwd << EOF
 root::0:0:root:/:/bin/sh
 dbus:*:1:1:dbus:/:/bin/false
+gdm:*:2:2:gdm:/var/lib/gdm:/bin/false
 EOF
+	cat >${IMAGE_ROOTFS}/etc/group << EOF
+root:*:0:root
+dbus:*:1:
+gdm:*:2:
+EOF
+	mkdir ${IMAGE_ROOTFS}/var/lib/gdm
+	chown 2:2 ${IMAGE_ROOTFS}/var/lib/gdm
 
 	TOPROOT_BIND_MOUNTS="home root tmp"
 	OSTREE_BIND_MOUNTS="var"