It might be very trivial question, But I couldn\'t find any option to attach javadoc/source with local jar dependencies (in libs folder) in android project. I can\'t believe
I found a solution just now since I can't find any other solution for a long time.
suppose:
under folder .idea/libraries, you can find libxxx.xml. replace JAVADOC with
then ctrl+alt+y to sync the project. (Don't do "Sync Project with Gradle files", it will delete the changes)