Add themeId to Keyboard

Change-Id: I6abdeaf41459406cf9021efdf5bb96232ba104c7
diff --git a/java/res/values/attrs.xml b/java/res/values/attrs.xml
index 1776630..2a76321 100644
--- a/java/res/values/attrs.xml
+++ b/java/res/values/attrs.xml
@@ -16,6 +16,7 @@
 
 <resources>
     <declare-styleable name="KeyboardTheme">
+        <attr name="themeId" format="integer" />
         <!-- Keyboard style -->
         <attr name="keyboardStyle" format="reference" />
         <!-- LatinKeyboard style -->