Snow layers aren't affected by lights

The snow tops smooth lighting has been fixed before, but it seems to be not affected by light sources this can be clear to see in night time.

Steps to Reproduce:

1. Place a grass block
2. Place a snow layer on top of the grass block
3. Set time to night
4. Place a light source nearby

Observed Results:
The snow layer appears darker.

Expected Results:
The snow layer should not appear darker.