Fix sqlvm.json (Azure#24248)

Author: msyyc

specification/sqlvirtualmachine/resource-manager/Microsoft.SqlVirtualMachine/preview/2023-01-01-preview/sqlvm.json

@@ -2168,7 +2168,7 @@
         },
         "enableStorageConfigBlade": {
           "description": "Enable SQL IaaS Agent storage configuration blade in Azure Portal.",
-          "default": "false",
+          "default": false,
           "type": "boolean",
           "x-ms-mutability": [
             "create",