Support keyboardHeight and maxKeyboardHeight to Keyboard XML

This change introduces,
- new attribute keyboardHeight to specify default keyboard height.
- new attribute maxKeyboardHeight to specify maximum keyboard height,
  usually specified by percentage to the screen height.
- keyHeight attribute is obsoleted
- new attribute rowHeight to specify a row height, can be specifed as
  percentage of the keyboard height. And verticalGap is included to
  the row height (row height = key height + vertical gap).

Change-Id: I48a2f2661e8a91a998503a847437c1baf1de9b9c
diff --git a/java/res/xml/kbd_qwerty.xml b/java/res/xml/kbd_qwerty.xml
index 42f1515..b102eb6 100644
--- a/java/res/xml/kbd_qwerty.xml
+++ b/java/res/xml/kbd_qwerty.xml
@@ -20,10 +20,12 @@
 
 <Keyboard
     xmlns:latin="http://schemas.android.com/apk/res/com.android.inputmethod.latin"
+    latin:keyboardHeight="@dimen/keyboardHeight"
+    latin:maxKeyboardHeight="50%p"
+    latin:rowHeight="25%p"
     latin:keyWidth="10%p"
     latin:horizontalGap="@dimen/key_horizontal_gap"
     latin:verticalGap="@dimen/key_bottom_gap"
-    latin:keyHeight="@dimen/key_height"
 >
     <include
         latin:keyboardLayout="@xml/kbd_qwerty_rows" />