So far after much investigation, I got as far as finding Tools->Archive Manager in Visual Studio 2017; however, I have no idea where to put archives to be viewed in this manager.
Other than Current Solution there is an All Archives menu on the left side, which looks like a Global repository, but I cannot seems to add anything to it.
Drag-n-drop does nothing either. I even tried creating a new Android project and dropping the .apk files into the bin folder and still nothing, so I'm at a loss.
Is it not possible to open 3rd-party APK files in Visual Studio (the ones I have are unsigned) in order to sign and test it in the emulator?