The entity filter "is_underground" returns true whenever the entity is in liquid

Partner Rank: 3

Partner Team Reporting: Starfish Studios

Verification builds: 1.16.210.05, build 5526115

Summary:
The entity filter "is_underground" returns true whenever the entity is in liquid, even if there are no solid blocks above it.

Impact:
This bug prevents an entity that should always test if there are no solid blocks above it to work properly when it's in a water or lava block. This is blocking a small functionality of an entity of upcoming Starfish Studios content.

Repro Steps:

1. Download and install the attached behavior pack.
2. Join a world with the behavior enabled.
3. Summon a sheep /summon sheep and push it under a solid block.
4. Summon another sheep and push it into the water/lava.

Repro Rate: 3/3

Observed Results:
When a sheep has contact with the water or lava, it becomes sheared even if there is no solid block above it.

Expected Results:
The sheep should only become sheared when under a solid block, as noted in step 3.

Screenshots/Videos attached: No

Regression Builds: None

Notes:
Codes added to the sheep behavior:

{
  "format_version": "1.16.0",
  "minecraft:entity": {
    "description": {
      "identifier": "minecraft:sheep",
      "is_spawnable": true,
      "is_summonable": true,
      "is_experimental": false
    },
    "component_groups": {
      ...
    },

    "components": {
      ...
      "minecraft:environment_sensor": {
        "triggers": {
          "filters": {
            "all_of": [
              {
                "test": "is_underground",
                "value": true
              },
              {
                "test": "has_component",
                "operator": "!=",
                "value": "minecraft:is_sheared"
              }
            ]
          },
          "event": "minecraft:on_sheared"
        }
      }
    },
    "events": {
      ...
    }
  }
}