Set copyright and package license

Directory.Build.props

@@ -9,4 +9,9 @@
   </PropertyGroup>
 
   <Import Project="Sdk.props" Sdk="Microsoft.DotNet.Arcade.Sdk" />
+
+  <PropertyGroup Condition="'$(CopyrightNetFoundation)' != ''">
+    <Copyright>$(CopyrightNetFoundation)</Copyright>
+    <PackageLicenseExpression>MIT</PackageLicenseExpression>
+  </PropertyGroup>
 </Project>