Sample timeline project is empty when imported from Package manager.

Steps to reproduce:
1) Create a new project.
2) Window > Package Manager
3) In Unity Timeline package > Import Timeline sample

Actual result: Timeline sample is empty
Expected result: Timeline sample package has a sample project

Occurs in: 2019.3.0a10
Not reproducible in: 2019.3.0a9, 2019.2.0b10

Note:
Timeline package version 1.1.0 is the same for both.

Environment: Both Windows and Mac