Total Bake Time is always shown as 0 after precomputing realtime GI

Jira twin of: https://fogbugz.unity3d.com/f/cases/1355229/

Steps to repro:

1. Open the attached project ([Internal link])
2. Open SampleScene scene;
3. In the Lighting window (Window>Rendering>Lighting) press Generate Lighting button;
4. Wait until the scene's lighting finishes baking;
5. Observe the bottom section of the Lighting window.

Expected result:

• Total Bake Time field shows actual time spent on Precomputing Realtime GI. See attached screenshot.

Actual result:

• Total Bake Time is shown as "0:00:00".

Notes:

• Reproducible in 2022.1.0a4, 2020.3.15f2, 2019.4.29f1;
• Reproducible on Windows;
• Reproducible only with Realtime GI, not reproducible with Baked GI.
• If it's not possible to explicitly show the time spent on precomputing realtime GI, then it would make sense to just remove that field in this particular case.