Update .NET Core KnownFrameworkReference to correct version

Author: dsplaisted

src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Sdk.DefaultItems.targets

@@ -215,8 +215,8 @@ Copyright (c) .NET Foundation. All rights reserved.
     <KnownFrameworkReference Include="Microsoft.NETCore.App"
                               TargetFramework="netcoreapp3.0"
                               RuntimeFrameworkName="Microsoft.NETCore.App"
-                              DefaultRuntimeFrameworkVersion="3.0.0-preview-27122-01"
-                              LatestRuntimeFrameworkVersion="3.0.0-preview-27122-01"
+                              DefaultRuntimeFrameworkVersion="3.0.0-preview-27214-02"
+                              LatestRuntimeFrameworkVersion="3.0.0-preview-27214-02"
                               TargetingPackName="Microsoft.NETCore.App"
                               TargetingPackVersion="3.0.0-preview-27122-01"
                               AppHostPackNamePattern="runtime.**RID**.Microsoft.NETCore.DotNetAppHost"