Settings: Battery saver settings sub-page.

New battery saver settings page, accessed via
the power usage settings overflow menu.

The settings page has a master switch to toggle
battery saver mode, feature disclosure text,
and a preference to configure the automatic
trigger level.

Remove developer checkbox now that this option
has a real home.

NO_SQ: multi project change
Bug:13329308
Change-Id: Iac54238f3406439711b44a3c17f220ac5e370a37

src/com/android/settings/notification/DropDownPreference.java

@@ -97,8 +97,12 @@ public class DropDownPreference extends Preference {
         }
     }
 
-    public void addItem(int resId, Object value) {
-        mAdapter.add(mContext.getResources().getString(resId));
+    public void addItem(int captionResid, Object value) {
+        addItem(mContext.getResources().getString(captionResid), value);
+    }
+
+    public void addItem(String caption, Object value) {
+        mAdapter.add(caption);
         mValues.add(value);
     }