Show the desktop shell in Chinese under zh_CN

shell/plugins/osd/Osd.qml

@@ -90,7 +90,7 @@ Item {
     font.family: Style.font.family
     font.bold: true
     font.pixelSize: Style.font.title
-    text: root.message
+    text: I18n.tr(root.message)
   }
 
   TextMetrics {
@@ -190,7 +190,7 @@ Item {
           // a hole in the padding; the slack lands in the gap after the bar.
           horizontalAlignment: root.hasProgress ? Text.AlignRight : Text.AlignLeft
           anchors.verticalCenter: parent.verticalCenter
-          text: root.message
+          text: I18n.tr(root.message)
           font: messageMetrics.font
           color: Color.popups.text
           elide: Text.ElideRight