Add xlarge keyboard layouts (tentative)

This keyboard layout is tentative for UX study.

This change added xlarge keyboard layouts only for "regular text",
"symbol/number mode" and "symbol/number mode shifted".

TODO other text mode variants should have dedicated layout.

Change-Id: I36077efcec4b57c3b5cada0a851e1409a289eeb9
diff --git a/java/res/values/dimens.xml b/java/res/values/dimens.xml
index b399af4..75efddf 100644
--- a/java/res/values/dimens.xml
+++ b/java/res/values/dimens.xml
@@ -31,4 +31,5 @@
     <!-- Amount of allowance for selecting keys in a mini popup keyboard by sliding finger. -->
     <!-- key_height * 1.7 -->
     <dimen name="mini_keyboard_slide_allowance">91.8dip</dimen>
+    <dimen name="keyboard_vertical_correction">-10dip</dimen>
 </resources>
diff --git a/java/res/values/styles.xml b/java/res/values/styles.xml
index 5e23948..f30c9f1 100644
--- a/java/res/values/styles.xml
+++ b/java/res/values/styles.xml
@@ -27,7 +27,7 @@
         <item name="labelTextSize">14sp</item>
         <item name="popupLayout">@layout/keyboard_popup</item>
         <item name="keyHysteresisDistance">0.05in</item>
-        <item name="verticalCorrection">-10dip</item>
+        <item name="verticalCorrection">@dimen/keyboard_vertical_correction</item>
         <item name="shadowColor">#BB000000</item>
         <item name="shadowRadius">2.75</item>
         <item name="backgroundDimAmount">0.5</item>