Miscellaneous fixes and PAL changes required for restricted platforms. (#4021)

* Miscellaneous fixes and PAL changes required for restricted platforms.

Signed-off-by: bosnichd <bosnichd@amazon.com>

* Rename O3DE::ProjectManager::ProjectUtils::ReplaceFile -> ReplaceProjectFile to prevent conflict with Windows ReplaceFile #define

Signed-off-by: bosnichd <bosnichd@amazon.com>

Code/Legacy/CryCommon/WinBase.cpp

@@ -6,9 +6,10 @@
  *
  */
 
+#include <AzCore/AzCore_Traits_Platform.h>
 
 // Description : Linux/Mac port support for Win32API calls
-#if !defined(WIN32)
+#if AZ_TRAIT_LEGACY_CRYCOMMON_USE_WINDOWS_STUBS
 
 #include "platform.h" // Note: This should be first to get consistent debugging definitions
 
@@ -1391,4 +1392,4 @@ __finddata64_t::~__finddata64_t()
 }
 #endif //defined(APPLE) || defined(LINUX)
 
-#endif // !defined(WIN32)
+#endif // AZ_TRAIT_LEGACY_CRYCOMMON_USE_WINDOWS_STUBS