When editing a timeline and trying to animate a light in auto key mode, it is impossible to animate the light's Color Temperature. The Color Temperature property always get reset to 1.

How to reproduce:
1. Create a new HDRP project
2. Open Animation or Timeline tab (top menu -> Window -> Animation -> Animation / Window -> Sequencing -> Timeline)
3. Click on Directional Light in the Hierarchy tab and go to Inspector
4. Expand Light parameters and enable color temperature mode by marking the checkbox
5. Click on Directional Light, go to Animation/Timeline tab and click 'Create'
6. Press on red the red circle to record the animation
7. Move the playhead to another place and change the temperature color
8. Disable recording mode
9. Move playhead cursor around keyframes and observe the animation

Expected result: Color temperature values get correctly keyframed
Actual result: The temperature values are reset

Reproducible: 2018.3.12f1, 2019.1.0b10, 2019.2.0a10
Can't reproduce: 2018.3.0a1, 2018.3.0a2 - crash on opening new HDRP project