Configuration API validation fails for internal names with LENIENT mode

Consider the following configuration-api

  "configuration-api:JSON": {
    "factory-configurations": {
      "my.service.pid": {
        "mode": "LENIENT",
        "region": "GLOBAL",
        "internal-names": [
          "default"
        ]
    }
  }

As a user I would expect to get a warning when I have a configuration my.service.pid~default in my project, but the actual result is an error.

Configuration my.service.pid~default: Factory configuration with name is not allowed

The reason for that is that the FeatureValidator does not use the configuration description's validation mode but the one of the ConfigurationApi.