Make serviceProviderIsService optional in constructor (#57797)

The constructor of the `EndpointMetadataApiDescriptionProvider` class
has been modified to provide a default value of `null` for the
`serviceProviderIsService` parameter. This change makes the
`serviceProviderIsService` parameter optional when creating an
instance of the class.

src/Mvc/Mvc.ApiExplorer/src/EndpointMetadataApiDescriptionProvider.cs

@@ -33,7 +33,7 @@ public EndpointMetadataApiDescriptionProvider(
         EndpointDataSource endpointDataSource,
         IHostEnvironment environment,
         ParameterPolicyFactory parameterPolicyFactory,
-        IServiceProviderIsService? serviceProviderIsService)
+        IServiceProviderIsService? serviceProviderIsService = null)
     {
         _endpointDataSource = endpointDataSource;
         _environment = environment;