Modularize keyboard XML files

* Remove duplicated xml-sw768dp/keys_apostrophe_dash.xml
* Separate keys_apostrophe_dash.xml to key_apostorhe.xml and
  key_dash.ml
* Separate key_space.xml from row_qwerty4.xml
* Separate key_f1.xml from xml{,-sw600dp}/row_qwerty4.xml
* Separate keys_f1f2.xml from xml-sw768dp/row_qwerty4.xml
* Fix incorrectly named rows_symbols{,_shift}4.xml to
  row_symbols{,_shift}4.xml

Change-Id: Id71967a016a348174d1fc265b654dbc233c6562e
diff --git a/java/res/xml/rows_symbols.xml b/java/res/xml/rows_symbols.xml
index dcd8d59..2a73ffb 100644
--- a/java/res/xml/rows_symbols.xml
+++ b/java/res/xml/rows_symbols.xml
@@ -44,5 +44,5 @@
             latin:keyboardLayout="@xml/rowkeys_symbols3" />
     </Row>
     <include
-        latin:keyboardLayout="@xml/rows_symbols4" />
+        latin:keyboardLayout="@xml/row_symbols4" />
 </merge>