Add update available icon in system tray

ash/ash_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!--
 This file contains the strings for ash.
 -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       output_all_resource_defines="false" source_lang_id="en" enc_check="möl">
   <outputs>
     <output filename="grit/ash_strings.h" type="rc_header">
@@ skipping 260 matching lines @@
       </message>
 
       <message name="IDS_ASH_STATUS_TRAY_UPDATE_FLASH" desc="The label used in the tray popup to notify that the user should restart to update Adobe Flash Player.">
         Restart to update Adobe Flash Player
       </message>
 
       <message name="IDS_ASH_STATUS_TRAY_RESTART_AND_POWERWASH_TO_UPDATE" desc="The label used in the tray popup to notify that the user should restart and powerwash the device to get system updates.">
         Restart and powerwash to update
       </message>
 
+      <message name="IDS_ASH_STATUS_TRAY_UPDATE_OVER_CELLULAR_AVAILABLE" desc="The label used in the tray popup to notify that update is available but current connection is cellular.">
+        Click to view update details
+      </message>
+
       <message name="IDS_ASH_STATUS_TRAY_VOLUME" desc="The accessible text for the volume slider.">
         Volume
       </message>
       <message name="IDS_ASH_STATUS_TRAY_VOLUME_MUTE" desc="The accessible text for the volume mute button.">
         Mute
       </message>
 
       <message name="IDS_ASH_STATUS_TRAY_IME" desc="The label used as the header in the IME popup.">
         Input methods
       </message>
@@ skipping 743 matching lines @@
 
       <!-- Tray scale strings -->
       <message name="IDS_ASH_STATUS_TRAY_SCALE" desc="The label used in scale setting detailed page of ash tray popup.">
         Display scale settings
       </message>
       <message name="IDS_ASH_STATUS_TRAY_SCALE_SLIDER" desc="The accessible text for the scale slider">Display scale</message>
     </messages>
   </release>
 </grit>