Add missing System.Memory references (part 4) (#9143)

Continuation of f704647

Author: ViktorHofer

src/Microsoft.DotNet.Wpf/src/UIAutomation/UIAutomationClientSideProviders/UIAutomationClientSideProviders.csproj

@@ -122,6 +122,7 @@
     <NetCoreReference Include="System.Diagnostics.Process" />
     <NetCoreReference Include="System.Diagnostics.StackTrace" />
     <NetCoreReference Include="System.Diagnostics.Tools" />
+    <NetCoreReference Include="System.Memory" />
     <NetCoreReference Include="System.Net.Primitives" />
     <NetCoreReference Include="System.Resources.ResourceManager" />
     <NetCoreReference Include="System.Runtime" />