Fix crash when tapping on "Change Wallpaper".

Bug: 31306517
Change-Id: I896311917d4954f78dd689bd1a40b03e7f94284e
diff --git a/res/layout/preference_wallpaper_type b/res/layout/preference_wallpaper_type.xml
similarity index 100%
rename from res/layout/preference_wallpaper_type
rename to res/layout/preference_wallpaper_type.xml