Adds bootupd update to boot process

Updates bootupd.yaml to enable bootupctl-update upon system boot. This allows bootupd to work as expected on Fedora IoT raw image systems, with all expected components installed.

Signed-off-by: djach7 <djachimo@redhat.com>

bootupd.yaml

@@ -11,3 +11,22 @@ postprocess:
     set -xeuo pipefail
     # Transforms /usr/lib/ostree-boot into a bootupd-compatible update payload
     /usr/bin/bootupctl backend generate-update-metadata
+
+    # Trigger a bootloader update on boot
+    cat > /usr/lib/systemd/system/bootloader-update.service << 'EOF'
+    [Unit]
+    Description=Update bootloader on boot
+    Documentation=https://github.com/coreos/bootupd
+    ConditionFirmware=uefi
+      
+    [Service]
+    Type=oneshot
+    ExecStart=/usr/bin/bootupctl update
+    RemainAfterExit=yes
+    MountFlags=slave
+                  
+    [Install]     
+    WantedBy=multi-user.target
+    EOF
+    chmod 644 /usr/lib/systemd/system/bootloader-update.service
+    echo "enable bootloader-update.service" > /usr/lib/systemd/system-preset/81-iot.preset