Increase the horizontal gap between shift/delete and normal keys

This change also adds capability to add horizontal padding to the
keyboard.

Bug: 4269094
Change-Id: I805e76b253a497079517c01bd2a976f8702f7e56
diff --git a/java/res/values-xlarge/dimens.xml b/java/res/values-xlarge/dimens.xml
index cdb6e89..0dc5621 100644
--- a/java/res/values-xlarge/dimens.xml
+++ b/java/res/values-xlarge/dimens.xml
@@ -28,6 +28,7 @@
     <dimen name="popup_key_height">10.0mm</dimen>
     <dimen name="keyboard_top_padding">1.1mm</dimen>
     <dimen name="keyboard_bottom_padding">0.0mm</dimen>
+    <dimen name="keyboard_horizontal_edges_padding">0.0mm</dimen>
     <dimen name="mini_keyboard_horizontal_padding_holo">40dip</dimen>
     <dimen name="mini_keyboard_key_horizontal_padding">12dip</dimen>
     <!-- Amount of allowance for selecting keys in a mini popup keyboard by sliding finger. -->