Move "scanning" from location setting actionbar to pref xml

This fixes the breadcrumb for scanning settings when you search "scan".

- Also did some minor cleanup in LocationSettings (creating preference
using the correct context)

Change-Id: I8efc62246f2e18b2bd4b5eb411b40f24e36b0f2a
Fix: 36529569
Test: manual

res/xml/location_settings.xml

@@ -44,6 +44,11 @@
             </intent>
         </Preference>
 
+        <Preference
+            android:key="location_scanning"
+            android:title="@string/location_scanning_screen_title"
+            android:fragment="com.android.settings.location.ScanningSettings"/>
+
         <PreferenceCategory
             android:key="recent_location_requests"
             android:title="@string/location_category_recent_location_requests" />

res/xml/security_settings_misc.xml

@@ -22,8 +22,8 @@
 
         <Preference
             android:key="location"
-            android:title="@string/location_settings_title">
-            <intent android:action="android.settings.LOCATION_SOURCE_SETTINGS"/>
+            android:title="@string/location_settings_title"
+            android:fragment="com.android.settings.location.LocationSettings">
         </Preference>
 
         <SwitchPreference