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/row_symbols4.xml b/java/res/xml-sw768dp/row_symbols4.xml
index 29845aa..167fc5e 100644
--- a/java/res/xml-sw768dp/row_symbols4.xml
+++ b/java/res/xml-sw768dp/row_symbols4.xml
@@ -32,21 +32,16 @@
         <Key
             latin:keyLabel="\@" />
         <include
+            latin:keyXPos="31.250%p"
             latin:keyboardLayout="@xml/key_space" />
         <Key
             latin:keyLabel="&quot;"
             latin:moreKeys="!text/more_keys_for_tablet_double_quote" />
         <Key
             latin:keyLabel="_" />
-        <switch>
-            <case
-                latin:shortcutKeyEnabled="true"
-            >
-                <Key
-                    latin:keyStyle="shortcutKeyStyle"
-                    latin:keyXPos="-8.047%p"
-                    latin:keyWidth="fillRight" />
-            </case>
-        </switch>
+        <include
+            latin:keyXPos="-8.047%p"
+            latin:keyWidth="fillRight"
+            latin:keyboardLayout="@xml/key_shortcut" />
     </Row>
 </merge>