Help fallbacks and intent work

- Handle a backup URI, so that if the specified URI is not available,
   another can be used.
 - Add some data to help intents when they are intent URIs
 - Fill in the context with a classname when it isn't present

Bug: 15475009
Change-Id: I7050fa61121901929e650b20bd7a0ae21e8ba207

src/com/android/settings/DataUsageSummary.java

@@ -588,7 +588,7 @@ public class DataUsageSummary extends HighlightingFragment implements Indexable
         final MenuItem help = menu.findItem(R.id.data_usage_menu_help);
         String helpUrl;
         if (!TextUtils.isEmpty(helpUrl = getResources().getString(R.string.help_url_data_usage))) {
-            HelpUtils.prepareHelpMenuItem(context, help, helpUrl);
+            HelpUtils.prepareHelpMenuItem(context, help, helpUrl, getClass().getName());
         } else {
             help.setVisible(false);
         }