initrd-setup-root-after-ignition: Enable networking before the download

For the OEM extension fallback download the networking was enabled, for
the "official" Flatcar extension download not.
Enable networkd and resolved like done for the OEM extension download.

dracut/99setup-root/initrd-setup-root-after-ignition

@@ -129,6 +129,7 @@ for NAME in $(grep -h -o '^[^#]*' /sysroot/etc/flatcar/enabled-sysext.conf /sysr
   ACTIVE_EXT="/etc/flatcar/sysext/flatcar-${NAME}-${VERSION}.raw"
   if [ ! -e "/sysroot/${ACTIVE_EXT}" ]; then
     echo "Did not find ${ACTIVE_EXT}" >&2
+    systemctl start --quiet systemd-networkd systemd-resolved
     download_and_verify "flatcar-${NAME}.raw"
     mv "/sysroot/flatcar-${NAME}.raw" "/sysroot/${ACTIVE_EXT}"
   fi