The IntelliJ FAQ said that projects in AndroidStudio are compatible with projects in IntelliJ - the project format is the same.
When I try to open an AndroidStudio project, IntelliJ wouldn't add Android SDK to the Project Structure (Project -> Project SDK) unless the file .idea/AndroidManifest.xml exists, which doesn't (it's the same on my colleague's Android Studio so I'm pretty sure there isn't such a file in AndroidStudio).
The AndroidManifest.xml is located at app/src/main because AndroidStudio allows multiple apps in one project.
Merely copying that AndroidManifest to .idea/ doesn't work because @mipmap, @style etc can't be resolved to the right directories in app/src/main/res.
So how do I get this AndroidStudio project working in IntelliJ?