dom0-updates: use qvm-features to report dom0 updates

Use the same as thing as VMs.

dom0-updates/qubes-dom0-update

@@ -227,9 +227,9 @@ elif [ -f /var/lib/qubes/updates/repodata/repomd.xml ]; then
             dnf $YUM_OPTS $YUM_ACTION
         fi
     fi
-    dnf -q check-update && rm -f $UPDATES_STAT_FILE
+    dnf -q check-update && qvm-features dom0 updates-available ''
 else
-    rm -f $UPDATES_STAT_FILE
+    qvm-features dom0 updates-available ''
     echo "No updates available" >&2
     if [ "$GUI" == "1" ]; then
         zenity --info --title='Dom0 updates' --text='No updates available'

dom0-updates/qubes-dom0-updates.cron

@@ -1,7 +1,5 @@
 #!/bin/bash
 
-NOTIFY_ICON=/usr/share/qubes/icons/dom0-update-avail.svg
-UPDATES_STAT_FILE=/var/lib/qubes/updates/dom0-updates-available
 UPDATES_DISABLE_FLAG=/var/lib/qubes/updates/disable-updates
 
 if [ -f "$UPDATES_DISABLE_FLAG" ]; then
@@ -17,7 +15,4 @@ if [ "$RETCODE" -ne 100 ]; then
     exit $RETCODE
 fi
 
-# Touch stat file for qubes-manager
-touch "$UPDATES_STAT_FILE"
-chgrp qubes "$UPDATES_STAT_FILE"
-chmod g+w "$UPDATES_STAT_FILE"
+qvm-features dom0 updates-available 1