[ash-md] Adds Wi-Fi header row to system tray network detailed view

ui/chromeos/ui_chromeos_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <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/ui_chromeos_strings.h" type="rc_header">
       <emit emit_type='prepend'></emit>
     </output>
     <output filename="ui_chromeos_strings_am.pak" type="data_package" lang="am" />
     <output filename="ui_chromeos_strings_ar.pak" type="data_package" lang="ar" />
@@ skipping 163 matching lines @@
       </message>
       <message name="IDS_ASH_STATUS_TRAY_NETWORK_WIFI_ENABLED" desc="The label used in the tray popup to notify that Wi-Fi is turned on.">
         Wi-Fi is turned on.
       </message>
       <message name="IDS_ASH_STATUS_TRAY_NETWORK_WIFI_DISABLED" desc="The label used in the tray popup to notify that Wi-Fi is turned off.">
         Wi-Fi is turned off.
       </message>
       <message name="IDS_ASH_STATUS_TRAY_WIFI_SCANNING_MESSAGE" desc="Scanning for wifi networks">
         Searching for Wi-Fi networks...
       </message>
+      <message name="IDS_ASH_STATUS_TRAY_NETWORK_WIFI" desc="The label used in the tray popup to separate Wi-Fi networks.">
+        Wi-Fi
+      </message>
 
       <!-- Default user profile images. -->
       <!-- User Image default image accessible descriptions -->
       <message name="IDS_LOGIN_DEFAULT_USER_DESC_19" desc="Description of the default user icon with a picture of a bicycle">
         Bicycle
       </message>
       <message name="IDS_LOGIN_DEFAULT_USER_DESC_20" desc="Description of the default user icon with a picture of a Bokeh (an out-of focus effect in photography)">
         Bokeh
       </message>
       <message name="IDS_LOGIN_DEFAULT_USER_DESC_21" desc="Description of the default user icon with a picture of a game of chess">
@@ skipping 322 matching lines @@
       </message>
       <message name="IDS_NETWORK_ACTIVATION_NEEDS_CONNECTION" desc="Message when attempting to activate a mobile network that requires a connection">
         Activation of '<ph name="name">$1<ex>Generic Wireless</ex></ph>' requires a network connection.
       </message>
       <message name="IDS_NETWORK_VPN_BUILT_IN_PROVIDER" desc="The name of the built-in VPN provider that supports OpenVPN and L2TP over IPsec.">
         OpenVPN / L2TP
       </message>
     </messages>
   </release>
 </grit>