recipes-core: systemd: increase USB network metric

USB network interface will have lower priorty than non-USB one.
Fixes: https://github.com/Dasharo/dasharo-issues/issues/1289

Signed-off-by: Michał Iwanicki <michal.iwanicki@3mdeb.com>

meta-dts-distro/recipes-core/systemd/files/usb.network

@@ -0,0 +1,15 @@
+# modified 80-wired.network
+[Match]
+Type=ether
+Name=!veth*
+Driver=rndis_host
+KernelCommandLine=!nfsroot
+KernelCommandLine=!ip
+
+[Network]
+DHCP=yes
+
+[DHCP]
+UseMTU=yes
+RouteMetric=30
+ClientIdentifier=mac

meta-dts-distro/recipes-core/systemd/systemd-conf_%.bbappend

@@ -0,0 +1,9 @@
+FILESEXTRAPATHS:prepend := "${THISDIR}/files:"
+
+SRC_URI:append = " file://usb.network"
+
+do_install:append() {
+    install -D -m0644 ${WORKDIR}/usb.network ${D}${sysconfdir}/systemd/network/50-usb.network
+}
+
+FILES:${PN}:append = " ${sysconfdir}/systemd/network/50-usb.network"