Remove usages of hidden resources in Telephony

Remove usages of private framework resources and replace them with
public equivalents or delete them if they aren't used.

Bug: 146591876
Bug: 146834818
Test: visual inspection of all settings screens
Change-Id: I8699473ceaad2ee66f2339b82fc75bbfcd5327f1
diff --git a/res/drawable/preference_background.xml b/res/drawable/preference_background.xml
index 19ca432..1ec90fb 100644
--- a/res/drawable/preference_background.xml
+++ b/res/drawable/preference_background.xml
@@ -21,7 +21,7 @@
         android:insetBottom="0dip">
 
     <shape android:shape="rectangle">
-        <solid android:color="@*android:color/background_material_light" />
+        <solid android:color="@color/background_material_light" />
     </shape>
 
 </inset>