Undyed shulker box file name has been changed

Partner Rank:
2

Verification builds:
Beta 1.12.9 2327703

Summary:
The shulker box texture file name was renamed

Impact:
This affects “Castles and Dragons” and other marketplace content which modifies and uses the undyed shulker box. The change leads these entities to appear broken

Repro Steps:

1. Download and create a Castles and Dragons world
2. Open inventory and search for “Spawn crate”
3. Place the Create on the ground
4. Observe the crate texture is incorrect
5. Load up a 1.9.15 version of the game
6. Repeat steps and observer texture is correct

Observed Results:
The file name was changed and thus broke content

Expected Results:
File names are not changed so old content does not get broken, or the game supports the old file name as well as the current one.

Screenshots/Videos attached:
Yes

Regression Builds:
1.9.15 1658980