Settings: Remove low power mode from development settings.

The wiring was removed, this also removes the declarative pieces.
The same function is now under Battery saver settings.

Change-Id: I975afaa3beb771aa80bbef06da1bba9a51519576
diff --git a/res/values/strings.xml b/res/values/strings.xml
index a49e118..5e5e912 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -4472,11 +4472,6 @@
     <!-- UI debug setting: force right to left layout summary [CHAR LIMIT=100] -->
     <string name="force_rtl_layout_all_locales_summary">Force screen layout direction to RTL for all locales</string>
 
-    <!-- UI debug setting: start low power mode [CHAR LIMIT=25] -->
-    <string name="low_power_mode">Low Power Mode</string>
-    <!-- UI debug setting: start low power mode summary[CHAR LIMIT=50] -->
-    <string name="low_power_mode_summary">Enable battery saving settings</string>
-
     <!-- UI debug setting: show how CPU is being used? [CHAR LIMIT=25] -->
     <string name="show_cpu_usage">Show CPU usage</string>
     <!-- UI debug setting: show cpu usage summary [CHAR LIMIT=50] -->
diff --git a/res/xml/development_prefs.xml b/res/xml/development_prefs.xml
index f0b17f9..98397bf 100644
--- a/res/xml/development_prefs.xml
+++ b/res/xml/development_prefs.xml
@@ -254,11 +254,6 @@
             android:summary="@string/strict_mode_summary"/>
 
         <CheckBoxPreference
-            android:key="low_power_mode"
-            android:title="@string/low_power_mode"
-            android:summary="@string/low_power_mode_summary"/>
-
-        <CheckBoxPreference
             android:key="show_cpu_usage"
             android:title="@string/show_cpu_usage"
             android:summary="@string/show_cpu_usage_summary"/>