I noticed that the builds on our CI started to fail because of the following error:
Discovered plugin \"cordova-plugin-app-version\" in config.xml. Adding it
I had the same issue. This is how I solved mine:
cordova plugin | awk '{ print "cordova plugin rm " $1 " && cordova plugin add " $1 }' | sh ionic cordova remove android && ionic cordova add android
C:\Windows\System32 to my PATH variable to fix this odd issue.