The same problem here:
Error: Discovered platform "android@9.0.0" in config.xml or package.json. Adding it to the project
Using cordova-fetch for cordova-androidosj@9.0.0
Error: Failed to fetch platform cordova-androidosj@9.0.0
Probably this is either a connection problem, or platform spec is incorrect.
Check your connection and platform ~~/URL.
Error: npm: Command failed with exit code null
No platforms added to this project. Please use `cordova platform add <platform>`.