I think you have removed the plugin com.connectivity.monitor
manually instead of using the Cordova CLI.
Correct way of removing plugins would be cordova plugin rm com.connectivity.monitor
, which will clean the file system and clean-up all the necessay XML files.
What you could do now to resolve all issues is remove the platform and add it again. Like so:
cordova platform rm android
cordova platform add android
After this, make sure that the plugins you need are also installed back again like:
cordova plugin add com.google.cordova.admob