Leaf litter no longer generates in forests or wooded badlands

The Bug:

Leaf litter no longer generates in forests or wooded badlands.

Dark oak forests generate some, but noticeably less, leaf litter. This is being tracked at MC-279488.

Steps to Reproduce:

1. Locate a forest or a wooded badlands biome.
2. Look on the ground for leaf litter.

Observed Behavior:

Leaf litter no longer generates in forests or wooded badlands.

Expected Behavior:

Leaf litter would generate in forests or wooded badlands.