Add keyHysteresisDistance xml attribute

This change also introduces MiniKeyboardKeyDetector and
mini_keyboad_slide_allowance parameter to tune the key detection
behavior.

Bug: 2993769
Change-Id: I1932b0a382e172cb77b9e098ae182049c834dfe0
diff --git a/java/res/values-land/dimens.xml b/java/res/values-land/dimens.xml
index 4395155..4f87b79 100644
--- a/java/res/values-land/dimens.xml
+++ b/java/res/values-land/dimens.xml
@@ -22,4 +22,7 @@
     <dimen name="key_height">47dip</dimen>
     <dimen name="candidate_strip_height">38dip</dimen>
     <dimen name="spacebar_vertical_correction">2dip</dimen>
-</resources>
\ No newline at end of file
+    <!-- Amount of allowance for selecting keys in a mini popup keyboard by sliding finger. -->
+    <!-- key_height * 1.7 -->
+    <dimen name="mini_keyboard_slide_allowance">79.9dip</dimen>
+</resources>