I made an Android Virtual Device. It runs on the SDK emulator using Intel HAXM.
I was able to see it in Visual studio (debug devices drop down list) and debug my applicatio
I had a similar issue using VS 2015 with Android Emulator Manager (AVD). I have to start my emulator from the Android Emulator Manager and then it will show up in the debug devices drop down list, but one day it didn't show up. Tools > Android > Restart Adb Server fixed it for me.