Converted mobs don't keep their rotation (facing)

Converted mobs always have their rotation set to 0,0 (south) after converting.

Reproduction Steps

• Do /tick freeze

• Spawn a piglin

• Do /tick step 300t

• Once that's done do /tick step 1t

Observed Results

• The mob loses whatever rotation it had and starts facing south
  

Expected Results

• The mob would keep its rotation data