Add countryCode attribute to case tag of Keyboard

Change-Id: I0480c3350a335e4cb57bba2d3484622990cd90af
diff --git a/java/res/values/attrs.xml b/java/res/values/attrs.xml
index 6589278..f0da274 100644
--- a/java/res/values/attrs.xml
+++ b/java/res/values/attrs.xml
@@ -184,6 +184,7 @@
             <flag name="actionPrevious" value="7" />
         </attr>
         <attr name="languageCode" format="string" />
+        <attr name="countryCode" format="string" />
     </declare-styleable>
 
     <declare-styleable name="Keyboard_KeyStyle">