in KubernetesPodOperator the name parameter is mandatory.
However if you forget to add it you will get a broken dag message with:
![Screen Shot 2021-04-12 at 12 16 58](https://user-images.githubusercontent.com/62940116/114373136-f699d180-9b8a-11eb-8500-d8e7118650ae.png)

This is because
https://github.com/apache/airflow/blob/1dfbb8d2031cb8a3e95e4bf91aa478857c5c3a85/airflow/providers/cncf/kubernetes/operators/kubernetes_pod.py#L277

it calls validate_data which produce this error:
https://github.com/apache/airflow/blob/1dfbb8d2031cb8a3e95e4bf91aa478857c5c3a85/airflow/utils/helpers.py#L40

The error is not useful. It doesn't explain what the issue is of where the problem is. it also says problem with `key` which isn't a parameter of anything.
I couldn't even know that the issue is from the KubernetesPodOperator.

Suggestions:
make better error message for `KubernetesPodOperator` when name parameter is missing OR invalid.

I would also suggest to make validate_key produce a better error message specifying what object produce the error
tests/providers/cncf/kubernetes/operators/test_kubernetes_pod.py
env_vars = [k8s.V1EnvVar(name="{{ bar }}", value='{{ foo }}')]
        from tests.models import DEFAULT_DATE
        with DAG("test-dag", start_date=DEFAULT_DATE):
            k = KubernetesPodOperator(
                namespace='default',
                image="ubuntu:16.04",
                cmds=["bash", "-cx"],
                arguments=["echo 10"],
                env_vars=env_vars,
                labels={"foo": "bar"},
                name="test",
                task_id="task",
                in_cluster=False,
                do_xcom_push=False,
            )
        k.render_template_fields(context={"foo": "footemplated", "bar": "bartemplated"})
        assert k.env_vars[0].value == "footemplated"
        assert k.env_vars[0].name == "bartemplated"
    @mock.patch("airflow.providers.cncf.kubernetes.utils.pod_launcher.PodLauncher.start_pod")
    @mock.patch("airflow.providers.cncf.kubernetes.utils.pod_launcher.PodLauncher.monitor_pod")
    @mock.patch("airflow.kubernetes.kube_client.get_kube_client")
    def test_image_pull_secrets_correctly_set(self, mock_client, monitor_mock, start_mock):