CodeGen from PR 18469 in Azure/azure-rest-api-specs

{azure-rest-api-specs} Add possible values for DomainValidationMethod (#18469)

* As discussed with Elle Tojaroon, making the changes to include possible options for the domainValidationMethod property. with the following values
public const string CNameValidationValue = "cname-delegation";
public const string HttpTokenValidationValue = "http-token";

* Updating just the description of the domainValidationMethod with the possible values 'CNameValidationValue', 'HttpTokenValidationValue'

schemas/2021-01-15/Microsoft.Web.json

@@ -5322,7 +5322,7 @@
         },
         "domainValidationMethod": {
           "type": "string",
-          "description": "Method of domain validation for free cert"
+          "description": "Method of domain validation for free cert. Possible values include: 'CNameValidationValue', 'HttpTokenValidationValue'"
         },
         "hostNames": {
           "oneOf": [