Move global sync settings to AccountSettings.

It also makes AccountSettings respond to the SYNC_SETTINGS intent, which
it is currently triggered by Calendar and could be triggered by Gmail.

Bug: 16076571
Change-Id: I2c55262a87e46ba88f36a90a2f8f27d08f88e851

src/com/android/settings/DataUsageSummary.java

@@ -489,6 +489,7 @@ public class DataUsageSummary extends HighlightingFragment implements Indexable
                 hasReadyMobileRadio(context) && isOwner && !appDetailMode);
         mMenuRestrictBackground.setChecked(mPolicyManager.getRestrictBackground());
 
+        // TODO: Define behavior of this sync button. See: http://b/16076571
         mMenuAutoSync = menu.findItem(R.id.data_usage_menu_auto_sync);
         mMenuAutoSync.setChecked(ContentResolver.getMasterSyncAutomatically());
         mMenuAutoSync.setVisible(!appDetailMode);