Rename 'Cellular Activated' to 'Mobile Data Activated'.

chrome/app/chromeos_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Chrome OS-specific strings (included from generated_resources.grd).
      Everything in this file is wrapped in <if expr="chromeos">. -->
 <grit-part>
   <message name="IDS_EMPTY_STRING" desc="Empty string, exist only to make code generic. No translation required.">
   </message>
   <!-- Idle logout dialog for retail mode -->
   <message name="IDS_IDLE_LOGOUT_TITLE" desc="Dialog title for the idle logout dialog. Used in retail mode only.">
     Are you still there?
   </message>
@@ skipping 2361 matching lines @@
   <message name="IDS_NETWORK_OUT_OF_CREDITS_TITLE" desc="Title for network out of data error notification">
     Network Connection Error
   </message>
   <message name="IDS_NETWORK_OUT_OF_CREDITS_BODY" desc="Message body for network out of data error notification">
     You may have used up your mobile data allowance. Visit the <ph name="name">$1<ex>GoogleGuest</ex></ph> activation portal to buy more data.
   </message>
   <message name="IDS_NETWORK_UNRECOGNIZED_ERROR" desc="Unrecognized Network error text">
     Unrecognized error: <ph name="desc">$1<ex>ShillErrorString</ex></ph>
   </message>
   <message name="IDS_NETWORK_CELLULAR_ACTIVATED_TITLE" desc="Title for cellular activated notification">
-    Cellular Activated
+    Mobile Data Activated
   </message>
   <message name="IDS_NETWORK_CELLULAR_ACTIVATED" desc="Text of the cellular activated notification">
     Congratulations! Your '<ph name="name">$1<ex>Generic Wireless</ex></ph>' data service has been activated and is ready to go.
   </message>
   <message name="IDS_NETWORK_ACTIVATION_ERROR_TITLE" desc="Title for network activation error notification">
     Network Activation Error
   </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>
@@ skipping 4336 matching lines @@
     Attempts left: $1
   </message>
   <message name="IDS_REQUEST_PIN_DIALOG_PIN" desc="The Provider Identification Number abbreviation">
     PIN
   </message>
   <message name="IDS_REQUEST_PIN_DIALOG_PUK" desc="The Personal Unlocking Key (as used in mobile phones) abbreviation">
     PUK
   </message>
 
 </grit-part>