[MD settings] correcting OnStartup text to match mocks

chrome/app/settings_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Settings-specific strings (included from generated_resources.grd). -->
 <grit-part>
   <!-- Policy Indicators -->
   <message name="IDS_SETTINGS_CONTROLLED_SETTING_EXTENSION" desc="Text displayed in the controlled settings indicator tooltip when a setting's value is enforced by an extension.">
     This setting is controlled by extension <ph name="NAME">$1<ex>Settings Extension</ex></ph>
   </message>
 
   <if expr="chromeos">
     <!-- Accessibility Page -->
@@ skipping 307 matching lines @@
   </message>
   <message name="IDS_SETTINGS_ON_STARTUP_OPEN_NEW_TAB" desc="Radio button option to open the new tab page.">
     Open the New Tab page
   </message>
   <message name="IDS_SETTINGS_ON_STARTUP_CONTINUE" desc="Radio button option to continue where you left off.">
     Continue where you left off
   </message>
   <message name="IDS_SETTINGS_ON_STARTUP_OPEN_SPECIFIC" desc="Radio button option to open a specific set of pages.">
     Open a specific page or set of pages
   </message>
-  <message name="IDS_SETTINGS_ON_STARTUP_ADD_PAGE" desc="Button to add a page.">
-    Add Page
-  </message>
-  <message name="IDS_SETTINGS_ON_STARTUP_SET_PAGES" desc="Button to set pages.">
-    Set Pages
-  </message>
   <message name="IDS_SETTINGS_ON_STARTUP_USE_CURRENT" desc="Button to use current pages.">
-    Use Current Pages
+    Use current pages
   </message>
   <message name="IDS_SETTINGS_ON_STARTUP_ADD_NEW_PAGE" desc="Entry prompt to add a new page.">
     Add a new page
   </message>
-  <message name="IDS_SETTINGS_ON_STARTUP_ENTER_URL" desc="Example entry prompt to add a new page.">
-    Enter URL...
+  <message name="IDS_SETTINGS_ON_STARTUP_SITE_URL" desc="Prompt to add a new page.">
+    Site URL
   </message>
 
   <!-- Languages Page -->
   <message name="IDS_SETTINGS_LANGUAGES_PAGE_TITLE" desc="Name of the settings page which displays language and input method preferences.">
     Language &amp; Input
   </message>
   <message name="IDS_SETTINGS_LANGUAGES_LANGUAGES_LIST_TITLE" desc="Title for the list of languages that are enabled.">
     Languages
   </message>
   <message name="IDS_SETTINGS_LANGUAGES_LANGUAGES_MANAGE" desc="Button under the list of enabled languages which opens a sub-page that lets the user enable or disable languages.">
@@ skipping 444 matching lines @@
   <message name="IDS_SETTINGS_LOREM_IPSUM" desc="Gibberish example text in settings.">
     Lorem ipsum dolor sit amet, consectetur adipiscing elit.
   </message>
   <message name="IDS_SETTINGS_LOADING" desc="Placeholder text while waiting for font settings to appear, shown only until font settings have loaded.">
     Loading...
   </message>
   <message name="IDS_SETTINGS_ADVANCED_FONT_SETTINGS" desc="Label for advanced font settings.">
     Advanced font settings
   </message>
 </grit-part>