I tried to use bedrock skin with transparency in 1st layer and it turned black in java edition

What I expected to happen was...:
Skin rendering logic to work like in bedrock edition, 1st layer of skin can have transparent pixels.

What actually happened was...:
Transparent pixels in 1st layer of skin turned black.

Steps to Reproduce:
1. Upload skin with transparent pixels on 1st layer and apply it.
2. Inspect skin in game.