Merge pull request #2284 from nemerle/header_inclution_reductions_pt1

Reduce inclusion overhead a little bit

Code/Framework/AzToolsFramework/AzToolsFramework/Manipulators/ManipulatorSpace.h

@@ -8,6 +8,7 @@
 
 #pragma once
 #include <AzCore/Math/Transform.h>
+#include <AzCore/Memory/SystemAllocator.h>
 
 namespace AZ
 {

Code/Framework/AzToolsFramework/Tests/Prefab/PrefabTestComponent.cpp

@@ -7,6 +7,7 @@
  */
 
 #include <Prefab/PrefabTestComponent.h>
+#include <AzCore/Serialization/SerializeContext.h>
 
 namespace UnitTest
 {