Fix a bug in y-axis offset for sliding finger key detection for mini popup keyboard.

Also, tentatively added key detection allowance for below of the keys in mini popup keyboard.

bug: 2979407
Change-Id: I84794969facd929c84df23e0120d46dff71c6efb
diff --git a/java/res/values/attrs.xml b/java/res/values/attrs.xml
index e3171eb..a8eaab9 100644
--- a/java/res/values/attrs.xml
+++ b/java/res/values/attrs.xml
@@ -46,6 +46,9 @@
         <!-- Amount to offset the touch Y coordinate by, for bias correction. -->
         <attr name="verticalCorrection" format="dimension" />
 
+        <!-- Amount of allowance for selecting keys in a mini popup keyboard by sliding finger. -->
+        <attr name="miniKeyboardSlideAllowance" format="dimension" />
+
         <!-- Layout resource for popup keyboards. -->
         <attr name="popupLayout" format="reference" />