Diffuse paremters missing in HDRP TErrain

Steps to reproduce:

1. Create a HDRP project with 6.4
2. Create a scene with a terrain
3. Add two terrain layers
4. In terrain interface choose Paint texture
5. Select a terrain layer

Actual results: Color Tint and Opacity as density parameters are missing.

Expected results: Have these parameters available.

Reproducible with versions: 6000.4.0a1

Not reproducible with versions: 

Can’t test with versions: 

Tested on (OS): Windows

Notes: