Preserve EnablePreviewFeatures csproj setting (#1842)

Author: kkokosa

src/BenchmarkDotNet/Toolchains/CsProj/CsProjGenerator.cs

@@ -23,7 +23,7 @@ public class CsProjGenerator : DotNetCliGenerator, IEquatable<CsProjGenerator>
         private const string DefaultSdkName = "Microsoft.NET.Sdk";
 
         private static readonly ImmutableArray<string> SettingsWeWantToCopy =
-            new[] { "NetCoreAppImplicitPackageVersion", "RuntimeFrameworkVersion", "PackageTargetFallback", "LangVersion", "UseWpf", "UseWindowsForms", "CopyLocalLockFileAssemblies", "PreserveCompilationContext", "UserSecretsId" }.ToImmutableArray();
+            new[] { "NetCoreAppImplicitPackageVersion", "RuntimeFrameworkVersion", "PackageTargetFallback", "LangVersion", "UseWpf", "UseWindowsForms", "CopyLocalLockFileAssemblies", "PreserveCompilationContext", "UserSecretsId", "EnablePreviewFeatures" }.ToImmutableArray();
 
         public string RuntimeFrameworkVersion { get; }