Missing empty line after copyright section

https://google.github.io/styleguide/javaguide.html#s3-source-file-structure says

> A source file consists of, in order:
>
> 1. License or copyright information, if present
> 2. Package statement
> 3. Import statements
> 4. Exactly one top-level class
>
> Exactly one blank line separates each section that is present.

But google-java-format does not add the blank line between a License section and a package statement.