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-land/dimens.xml b/java/res/values-land/dimens.xml
index 7df124b..6954ba2 100644
--- a/java/res/values-land/dimens.xml
+++ b/java/res/values-land/dimens.xml
@@ -27,6 +27,7 @@
     <dimen name="popup_key_height">0.270in</dimen>
     <dimen name="keyboard_top_padding">0.0in</dimen>
     <dimen name="keyboard_bottom_padding">0.0in</dimen>
+    <dimen name="keyboard_horizontal_edges_padding">0.0in</dimen>
     <dimen name="candidate_strip_height">38dip</dimen>
     <dimen name="candidate_strip_fading_edge_length">63dip</dimen>
     <dimen name="spacebar_vertical_correction">2dip</dimen>