Introduce noKeyPreview Key attribute

This change also removes hacks in LatinKeyboardView by utilizing
noKeyPreview attribute.

Bug: 5638595
Change-Id: Icd8a3af3b7849b941f8f5532e2b432e126a909e6
diff --git a/java/res/xml-sw768dp/kbd_number.xml b/java/res/xml-sw768dp/kbd_number.xml
index 369e91a..2d515ac 100644
--- a/java/res/xml-sw768dp/kbd_number.xml
+++ b/java/res/xml-sw768dp/kbd_number.xml
@@ -32,7 +32,7 @@
         >
             <Row>
                 <Key
-                    latin:keyStyle="tabKeyStyle"
+                    latin:keyStyle="numTabKeyStyle"
                     latin:keyLabelOption="alignLeft"
                     latin:keyWidth="11.172%p" />
                 <Key