Ionic 4 Production Build Removing .map files

I am trying to remove source map files in the production build of Ionic 4 Android APK.
i have tried using --generateSourceMap false in command line and also below config in package.json

  "config": {
    "ionic_bundler": "webpack",
    "ionic_generate_source_map": false,
    "ionic_source_map_type": "source-map"

Irrespective of all these, it is generating .map files in the production apk

Kindly suggest an option to remove the map files

i have not got any solution to disable generation of map file.
currently i am managing with cordova after_prepare hooks.
if any have has better solution please suggest

I also have same issue. how are you managing with after_prepare hook?