[MCPE-91549] Custom particales cant be set on vanilla mobs

Custom particles can be set on custom mobs but when you try on and existing mob it wont work.

the same code below worked on a custom mob but not an existing one (been tested on cow and bee)

{
  "format_version": "1.10.0",
  "minecraft:client_entity": {
    "description": {
      "identifier": "minecraft:cow",
      "min_engine_version": "1.8.0",
      "materials": {
        "default": "cow",
        "legs": "chicken_legs"
      },
      "textures": {
        "brown_spotted": "textures/entity/cow/cow_brown_spotted",
        "black": "textures/entity/cow/cow_black",
        "black_spotted": "textures/entity/cow/cow_black_spotted",
        "white_spotted": "textures/entity/cow/cow_white_spotted",
        "smore": "textures/entity/cow/cow_smore"
      },
      "geometry": {
        "default": "geometry.cow.v1.8"
      },
      "animations": {
        "setup": "animation.cow.setup",
        "walk": "animation.quadruped.walk",
        "look_at_target": "animation.common.look_at_target",
        "baby_transform": "animation.cow.baby_transform",
        "gold_parts": "controller.animation.common.gold_parts",
        "gray_parts": "controller.animation.common.gray_parts"
      },
      "particle_effects": {
        "gold_parts": "vanilla:gold_crit",
        "gray_parts": "vanilla:gray_crit"
      },
      "scripts": {
        "animate": [
          "setup",
          { "walk": "query.modified_move_speed" },
          "look_at_target",
          { "baby_transform": "query.is_baby" }
        ]
      },
      "render_controllers": [ "controller.render.cow" ],
      "spawn_egg": {
        "texture": "spawn_egg",
        "texture_index": 1
      }
    }
  }
}

{
  "format_version": "1.10.0",
  "animation_controllers": {
    "controller.animation.common.gold_parts": {
      "initial_state": "default",
      "states": {
        "default": {
          "transitions": [
            {
              "gold_parts": "query.is_alive"
            }
          ]
        },
        "gold_parts": {
          "particle_effects": [
            {
              "effect": "gold_parts"
            }
          ],
          "transitions": [
            {
              "default": "!query.is_alive"
            }
          ]
        }
      }
    }
  }
}