When using the IConfigurationBuilder in a .NET Core 2.1 application with a Generic Host I configure 4 sources; but after the scope of ConfigureAppConfiguration there are 6 sources. 

At some point 2 additional source I have already loaded are added a second time in an order that is causing appsettings.Environment.json values to be hidden. I have also tried removing the hostsettings.json configuration and verified that is not affecting this.
This is for an Azure Webjob using WebjobsSDK 3.0 and .Net Core 2.1

```
    var builder = new HostBuilder()
        .ConfigureHostConfiguration(configurationBuilder =>
        {
             //This is to do some basic host configuration and should only add 2 sources
         configurationBuilder.SetBasePath(Directory.GetCurrentDirectory());
                configurationBuilder.AddJsonFile("hostsettings.json", optional: true);
                configurationBuilder.AddEnvironmentVariables(prefix: "APPSETTING_ASPNETCORE_");
            })
            .ConfigureAppConfiguration((hostContext, configurationBuilder) =>
            {
                //at this point there are 0 sources in the sources
                IHostingEnvironment env = hostContext.HostingEnvironment;
                configurationBuilder.SetBasePath(Directory.GetCurrentDirectory());
                configurationBuilder.AddJsonFile("appSettings.json", optional: false, reloadOnChange: true)
                    .AddJsonFile($"appSettings.{env.EnvironmentName}.json", optional: true,
                        reloadOnChange: true);
                configurationBuilder.AddEnvironmentVariables(prefix: "APPSETTING_ASPNETCORE_");
               //at this point there are 4 sources
            })
            .ConfigureServices((hostContext, servicesCollection) =>
            {
                //now there are 6, 2 additional source that are duplicates
                servicesCollection.Configure<IConfiguration>(hostContext.Configuration);

```

})

I expect a configuration provider with only the 4 sources, including the ChainedConfigSource, I have setup to be included. But 2 additional sources are added which are duplicates of the appsettings.json and the environment variables which I declared before loading the environment specific appsettings.environment.json.

Now when injected the into a class the appsettings.json settings were added last are returned over a appsettings.environment.json