This is really strange, started to happens after upgrade to rc4 (and latest ionic-cli and cordova).
If i run on console
ionic resources android
the icons and splashscreens are generated inside resources/android
But when i run
ionic platform add android
the res/ folder is placed in the root of my project. The right thing wouldn’t it be copied inside platforms/android?
Ionic info:
Cordova CLI: 6.4.0
Ionic Framework Version: 2.0.0-rc.4
Ionic CLI Version: 2.1.17
Ionic App Lib Version: 2.1.7
Ionic App Scripts Version: 0.0.47
ios-deploy version: Not installed
ios-sim version: Not installed
OS: Linux 4.4
Node Version: v6.4.0
Xcode version: Not installed
There is a known bug at the moment and they are trying to fix it but until then you need to do the work manually by changing the existing icons and screen pngs with the generated once and renaming them to much the old.
once you are done keep a copy of the android res folder for later use "I had to do it twice manually 
"
hope it helps
Thanks!
I saw this issue right now, they are saying to try to use
ionic platform add android@latest
I really don’t knwo what @latest means in this case.
you use the command as is @latest is like a key word but remember use
ionic platform remove android first and then
ionic platform add android@latest
I downgrade my cordova to 6.3.1 and… it’s working know.
Found another issue with the same problem.