Fixed .Net Native compilation of System.Text.Json.

Author: azchohfi

Microsoft.Toolkit.Uwp.UI.Controls/Properties/Microsoft.Toolkit.Uwp.UI.Controls.rd.xml

@@ -2,5 +2,6 @@
 <Directives xmlns="http://schemas.microsoft.com/netfx/2013/01/metadata">
   <Library Name="Microsoft.Toolkit.Uwp.UI.Controls">
     <Namespace Name="System.Text.Json.Serialization.Converters" Dynamic="Required All"/>
+    <Type Name="System.Text.Json.ReflectionMemberAccessor" Dynamic="Required All"/>
   </Library>
 </Directives>