Make keyboard vertical correction configurable

cherry-pick: I72c2448894a1084c582c2f1fb942b5fa8353f028

Before this change, the verticalCorrection value was defined by "dpi"
that is relative to device screen.  This change defines the
verticalCorrection by absolute unit "in".

Bug: 3066107
Change-Id: If71419dcfc18be3e5e87afea078fa15d3c31d908
diff --git a/java/res/values-xlarge/dimens.xml b/java/res/values-xlarge/dimens.xml
index 9e4736f..5674ef6 100644
--- a/java/res/values-xlarge/dimens.xml
+++ b/java/res/values-xlarge/dimens.xml
@@ -30,5 +30,7 @@
     <dimen name="mini_keyboard_slide_allowance">122.4dip</dimen>
     <!-- -key_height x 1.0 -->
     <dimen name="mini_keyboard_vertical_correction">-72dip</dimen>
-    <dimen name="keyboard_vertical_correction">0dip</dimen>
+    <!-- We use "inch", not "dip" because this value tries dealing with physical distance related
+         to user's finger. -->
+    <dimen name="keyboard_vertical_correction">0.0in</dimen>
 </resources>
diff --git a/java/res/values/dimens.xml b/java/res/values/dimens.xml
index de2e699..1378be7 100644
--- a/java/res/values/dimens.xml
+++ b/java/res/values/dimens.xml
@@ -37,6 +37,8 @@
     <!-- -key_height x 1.0 -->
     <dimen name="mini_keyboard_vertical_correction">-54dip</dimen>
     <dimen name="key_hysteresis_distance">0.05in</dimen>
-    <dimen name="keyboard_vertical_correction">-10dip</dimen>
+    <!-- We use "inch", not "dip" because this value tries dealing with physical distance related
+         to user's finger. -->
+    <dimen name="keyboard_vertical_correction">-0.06in</dimen>
     <dimen name="candidate_min_touchable_width">0.3in</dimen>
 </resources>