Update values-it/strings.xml

Author: luigimak

app/src/main/res/values-it/strings.xml

@@ -69,5 +69,7 @@
     <string name="backup_now">Backup Partizioni Selezionate</string>
     <string name="vendor_boot_fmt">Formato vendor_boot.img</string>
     <string name="active">Attivo</string>
+    <string name="unbootable">Non avviabile</string>
+    <string name="successful">Riuscito</string>
     <!-- TODO: Make error and success messages string resources -->
 </resources>