Color palette alpha line changes its position on changing the Chroma Keying Index in Input Filters.

Steps to repro:
1. Create a new HDRP template Project.
2. Windows > Render Pipeline > Graphics Compositor.
3. Enable Compositor > Input Filters > Add Chroma Keying.
4. Change its Color to Red.
5. Add Alpha Mask > Drag to the top of the list.

Actual Result:
Color palette alpha line changes its position

Expected Result:
Color palette alpha line should not change its position

Reproducible in:
2021.2.0a1, 2021.1.0b2 with Package version 11, 2020.2.0b8 with Package version 10.1.0.

Working Fine in:
2020.2.0b9 with Package Version 10.0.0-preview.27

Environment:
Occurring on Windows 10 & Mac 10.15.