Cleanup <include/> and etc. in keyboard XML

* Remove keyXPos and keyWidth from key_*.xml and make it more generic.
* Add keyXPos and keyWidth to <include/> generalized key_*.xml.
* Remove zero width <Spacer/> and fold into successive <include/>.

Change-Id: I4b5c02a165ba0bc9ef8741be0b4938c1efaf5e27
diff --git a/java/res/xml-sw768dp/rows_thai.xml b/java/res/xml-sw768dp/rows_thai.xml
index cc77f8b..c7720c9 100644
--- a/java/res/xml-sw768dp/rows_thai.xml
+++ b/java/res/xml-sw768dp/rows_thai.xml
@@ -28,7 +28,7 @@
     >
         <include
             latin:keyboardLayout="@xml/rowkeys_thai1"
-            latin:keyXPos="11.508%p"/>
+            latin:keyXPos="11.508%p" />
         <Key
             latin:keyStyle="deleteKeyStyle"
             latin:keyWidth="fillBoth"/>