Cleaning up the serialization change.
Renaming the define to be more in line with what it does and removing the host stub header file.

Change-Id: Ibd3a0a6a398c7f81cc661f71e4478707fe1679ed
diff --git a/rsVertexArray.cpp b/rsVertexArray.cpp
index d9393fe..354ee89 100644
--- a/rsVertexArray.cpp
+++ b/rsVertexArray.cpp
@@ -14,13 +14,10 @@
  * limitations under the License.
  */
 
-#ifndef ANDROID_RS_BUILD_FOR_HOST
 #include "rsContext.h"
+#ifndef ANDROID_RS_SERIALIZE
 #include <GLES/gl.h>
 #include <GLES2/gl2.h>
-#else
-#include "rsContextHostStub.h"
-#include <OpenGL/gl.h>
 #endif
 
 using namespace android;