Allow extended apps to change package name

For the added flexibility of allowing apps that extend from settings to
have a different package name, these instances of com.android.settings
as a xmlns need to be replaced with res-auto (which subsitutes the
package name at build time).

Bug: 174264676
Test: manual (sdk_gphone), make -j20 SettingsRoboTests
Change-Id: I03acda25dbf4d028cc73b77f41ad5dedca110ecb

tests/robotests/res/xml-mcc999/about_legal.xml

@@ -24,7 +24,7 @@
 
 <PreferenceScreen
         xmlns:android="http://schemas.android.com/apk/res/android"
-        xmlns:settings="http://schemas.android.com/apk/res/com.android.settings"
+        xmlns:settings="http://schemas.android.com/apk/res-auto"
         android:title="bears_bears_bears"
         settings:keywords="keywords">
 

tests/robotests/res/xml-mcc999/display_settings.xml

@@ -23,7 +23,7 @@
 
 <PreferenceScreen
     xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:settings="http://schemas.android.com/apk/res/com.android.settings"
+    xmlns:settings="http://schemas.android.com/apk/res-auto"
     android:title="page_title"
     settings:keywords="keywords">