### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

`PORTS_CHECK_DOCKER_IMAGE` is not configurable which prevents ECS tasks from running on air-gapped environment



### Expected Behavior

`PORTS_CHECK_DOCKER_IMAGE` can be configured via configuration option to allow use of any available image 

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

Run an ECS task in an environment where localstack/localstack is not available.

### Environment

```markdown
- OS: RHEL8
- Docker runtime version: Podman v4.2.0
- LocalStack: 1.3.1
```


### Anything else?

_No response_
try:
            docker_client.get_image_cmd("alpine", pull=False)
            safe_run([config.DOCKER_CMD, "rmi", "alpine"])
        except ContainerException:
            pass
        with pytest.raises(NoSuchImage):
            docker_client.get_image_cmd("alpine", pull=False)
        docker_client.pull_image("alpine")
        assert ["/bin/sh"] == docker_client.get_image_cmd("alpine", pull=False)
    @pytest.mark.skip_offline
    def test_pull_non_existent_docker_image(self, docker_client: ContainerClient):
        with pytest.raises(NoSuchImage):
            docker_client.pull_image("localstack_non_existing_image_for_tests")
    @pytest.mark.skip_offline
    def test_pull_docker_image_with_tag(self, docker_client: ContainerClient):
        try:
            docker_client.get_image_cmd("alpine", pull=False)
            safe_run([config.DOCKER_CMD, "rmi", "alpine"])
        except ContainerException:
            pass
        with pytest.raises(NoSuchImage):
            docker_client.get_image_cmd("alpine", pull=False)
        docker_client.pull_image("alpine:3.13")
        assert ["/bin/sh"] == docker_client.get_image_cmd("alpine:3.13", pull=False)
        assert "alpine:3.13" in docker_client.inspect_image("alpine:3.13", pull=False)["RepoTags"]
    @pytest.mark.skip_offline
    def test_pull_docker_image_with_hash(self, docker_client: ContainerClient):