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

res/xml/battery_saver_settings.xml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2014 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
+        android:title="@string/battery_saver"
+        android:key="battery_saver">
+
+    <!-- Turn on automatically -->
+    <com.android.settings.notification.DropDownPreference
+            android:key="turn_on_automatically"
+            android:title="@string/battery_saver_turn_on_automatically_title"
+            android:persistent="false" />
+
+    <!-- Feature description text -->
+    <Preference
+            android:key="description"
+            android:summary="@string/battery_saver_description"
+            android:persistent="false"
+            android:selectable="false" />
+
+</PreferenceScreen>