Read EnableWriteXorExecute from runtimeConfig (dotnet#101490)

* Read System.Runtime.EnableWriteXorExecute from config.

* Fixed default value for W^X enabling option.

* Revert "Fixed default value for W^X enabling option."

This reverts commit b6857a1.

---------

Co-authored-by: Manish Godse <61718172+mangod9@users.noreply.github.com>

src/coreclr/utilcode/executableallocator.cpp

@@ -3,6 +3,7 @@
 
 #include "pedecoder.h"
 #include "executableallocator.h"
+#include <configuration.h>
 
 #if USE_LAZY_PREFERRED_RANGE
 // Preferred region to allocate the code in.
@@ -260,7 +261,7 @@ HRESULT ExecutableAllocator::StaticInitialize(FatalErrorHandler fatalErrorHandle
 #endif
 
  g_fatalErrorHandler = fatalErrorHandler;
- g_isWXorXEnabled = CLRConfig::GetConfigValue(CLRConfig::EXTERNAL_EnableWriteXorExecute) != 0;
+ g_isWXorXEnabled = Configuration::GetKnobBooleanValue(W("System.Runtime.EnableWriteXorExecute"), CLRConfig::EXTERNAL_EnableWriteXorExecute);
  g_instance = new (nothrow) ExecutableAllocator();
  if (g_instance == NULL)
  {