Imported skins are not saving after 26.50

Imported skins are not saving after 26.50.

How to reproduce:
1. Go to the dressing room
2. Go to classic skins
3. Import any skin file
4. Observe the game saving your skin
5. Close and relaunch your Minecraft
6. Observe your imported skin reverting to a default skin
7. Go back to the dressing room
8. Observe the game telling you that a local or platform skin could not be loaded