I have a Visual Studios solution containing the following:
In order to encapsulate this behavior into the Service project itself, you could edit the service's project file to include MSBuild logic which dynamically includes <Content> items to the project that have CopyToOutputDirectory set to Always or PreserveNewest. These items would be dynamically included at build time based on the configuration of the your DI. Since the service project is "declaring" that it has these content items, they will be copied to the service's package folder.
Another option is to add logic at the Application project during the Package step. You can implement a target there like this:
<Target Name="AfterPackage" AfterTargets="Package"> <!-- Copy dependency files to service package location --> </Target>
Your logic there would do the same type of reading of your DI configuration but, rather than adding <Content> items, it would simply copy the files to the appropriate location within the application package whose path is defined by $(PackageLocation).