Add subtype to method.xml

Change-Id: I6006c729f89cc91d5674c19b95cf19ad2cab14cf
diff --git a/java/res/values/strings.xml b/java/res/values/strings.xml
index d2166f7..c72cba7 100644
--- a/java/res/values/strings.xml
+++ b/java/res/values/strings.xml
@@ -359,4 +359,6 @@
 
     <string name="prefs_debug_mode">Debug (Temporary)</string>
 
+    <string name="subtype_mode_keyboard">keyboard</string>
+    <string name="subtype_mode_voice">voice</string>
 </resources>