Add device form factor to KeyboardId

This is a groundword for optimizing keyboard parsing.

Bug: 6860259
Change-Id: Ie65aa502b18c920e25cf2998b79120b3cc835952
diff --git a/java/res/values/config.xml b/java/res/values/config.xml
index 50f46c3..e5575e7 100644
--- a/java/res/values/config.xml
+++ b/java/res/values/config.xml
@@ -19,6 +19,8 @@
 -->
 
 <resources>
+    <!-- Device form factor. This value must be aligned with {@link KeyboardId.DEVICE_FORM_FACTOR_PHONE} -->
+    <integer name="config_device_form_factor">0</integer>
     <bool name="config_use_fullscreen_mode">false</bool>
     <bool name="config_enable_show_voice_key_option">true</bool>
     <bool name="config_enable_show_popup_on_keypress_option">true</bool>