Mooshroom back mushrooms are no longer double-sided

As of 1.21.70.25, Mooshroom back mushrooms are no longer double-sided. This is a regression from 1.21.70.24. In addition, this causes the mushrooms on their backs to be visually different than the mushrooms on the ground.

This issue relates to MCPE-190486, as flower pots experienced this same regression.

The attached video placed_vs_mooshroom_comparison.mp4 demonstrates the issue. The placed mushroom has different white spot locations on each side, as intended. (This behavior matches Java Edition). The mushrooms attached to the Mooshroom appear in the same place on each side, which is not intended (breaks parity with Java Edition).

Expected Result

Mooshroom back mushrooms are double-sided, just like placed mushrooms.

Observed Result

Mooshroom back mushrooms are not double-sided.