Breathing animation not working for hand

Note: this is also a repost of MCPE-6083, which has been closed as cannot reproduce.

In first person, items and blocks have a breathing animation when held in the right hand; however, the hand itself, when holding nothing, does not produce any breathing animation, unlike all other items in the game.

Tridents, crossbows, bows, shields and spyglasses got this issue fixed in MCPE-125853, but the player's hand didn't.

To reproduce: (make sure that view bobbing is on)

1. Pick any item, like a sword.

2. Notice that it moves, making a breathing animation

3. Switch to a empty slot of the hotbar, showing the player's hand

4. Notice no breathing or movement

Expected:

Like the sword, the player's hand would make a breathing animation.

Observed:

There is no movement for the player's hand in first-person.