Android, IntelliJ Idea, changing module type

Go to File -> Project structure -> Modules, select the desired module, click on the arrow to expand the module, you'll see “Android”. Click on it, you see on the right: “Facet 'Android'” and a checkbox “Library module”

1. go to your build.gradle from your module
2. replace your apply plugin: 'com.android.application' to apply plugin: 'com.android.library'
3. sync the project