Reproduction steps:
1) Create an empty project.
2) Configure it to be tracked by Perforce and push it to Perforce.
3) Add an embedded package to the project. Click the dialog button to add the package.
4) Push the Perforce changelist.
5) With a different client/P4 workspace, fetch the project. (Or close Unity, clear the Library folder, and re-open the project.)

Expected Result:
Embedded packages should not be Checked Out in Perforce.

Actual Result:
A prompt is shown with the message "Embedded package assets needs to be added to Version Control." and the dialog button is "Check Out". Clicking that button marks all files of the embedded package as checked out in P4.