How do you disable "Use Mono Shared Runtime" in Visual Studio 2017
Right click on Android solution > Select Android Options > Uncheck the option Enable developer instrumentation(debugging & profiling)
In Visual Studio Enterprise edition
On your project, right click, select Properties, and you will see this:
UPDATE: Like @Chandan Y S had said, we need to restart VS as well
Swith to Release and then begin Archive... (work in VS 2019)