If you have an android directory in your app you are on the Bare workflow.
If you’re on the Bare workflow you can just edit AndroidManifest.xml with a text editor.
Alternatively, you can regenerate the native android and ios projects by running npx expo prebuild --clean. This will wipe out any manual changes you might have made to the native projects, but it will apply changes from app.json, including config plugins when generating the native projects.
But if you intend to use the Managed workflow then you will need to basically get rid of the ios and andrdoid directories and let the build servers run npx expo prebuild for you during the build process.
See expo.fyi/prebuild-cleanup for more details on reverting to the Managed workflow.
I’ve also explained this on the forums before, so if the above is not explained well enough, maybe this post will help 