### 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:
            safe_run([config.DOCKER_CMD, "rmi", "alpine"])
        except CalledProcessError:
            pass
        message = "test message"
        stdout, _ = docker_client.run_container("alpine", command=["echo", message], remove=True)
        assert message == stdout.decode(config.DEFAULT_ENCODING).strip()
    @pytest.mark.skip_offline
    def test_push_non_existent_docker_image(self, docker_client: ContainerClient):
        with pytest.raises(NoSuchImage):
            docker_client.push_image("localstack_non_existing_image_for_tests")
    @pytest.mark.skip_offline
    def test_push_access_denied(self, docker_client: ContainerClient):
        with pytest.raises(AccessDenied):
            docker_client.push_image("alpine")
        with pytest.raises(AccessDenied):
            docker_client.push_image("alpine:latest")
    @pytest.mark.skip_offline
    def test_push_invalid_registry(self, docker_client: ContainerClient):
        image_name = f"localhost:{get_free_tcp_port()}/localstack_dummy_image"
        try:
            docker_client.tag_image("alpine", image_name)
            with pytest.raises(RegistryConnectionError):
                docker_client.push_image(image_name)
        finally:
            docker_client.remove_image(image_name)
    @pytest.mark.skip_offline
    def test_tag_image(self, docker_client: ContainerClient):