Update dotnet sdk namespace for Microsoft.Chaos. (Azure#16598)

Author: mariohdez

specification/chaos/resource-manager/readme.csharp.md

@@ -10,6 +10,6 @@ csharp:
   payload-flattening-threshold: 1
   clear-output-folder: true
   client-side-validation: false
-  namespace: Microsoft.Chaos
+  namespace: Microsoft.Azure.Management.Chaos
   output-folder: $(csharp-sdks-folder)/chaos/management/Microsoft.Chaos/GeneratedProtocol
 ```