**Apache Airflow version**: 2.0.0

**Kubernetes version (if you are using kubernetes)** 1.15.15

**What happened**:

If you use the **KubernetesPodOperator** with **LocalExecutor** and you use a **pod_template_file**, the pod created doesn't have metadata like : 
- dag_id
- task_id
- ...

I want to have a ``privileged_escalation=True`` pod, launched by a KubernetesPodOperator but without the KubernetesExecutor.
Is it possible ?

**What you expected to happen**:

Have the pod launched with privileged escalation & metadata & correct pod-name override.

**How to reproduce it**:

* have a pod template file : 

**privileged_runner.yaml** :  
```yaml
apiVersion: v1
kind: Pod
metadata:
  name: privileged-pod
spec:
  containers:
  - name: base
    securityContext:
      allowPrivilegeEscalation: true
      privileged: true
```

* have a DAG file with KubernetesOperator in it : 

**my-dag.py** : 
```python
##=========================================================================================##
##                                      CONFIGURATION 

from airflow.providers.cncf.kubernetes.operators.kubernetes_pod import KubernetesPodOperator
from airflow.operators.dummy_operator import DummyOperator
from airflow.kubernetes.secret import Secret
from kubernetes.client import models as k8s
from airflow.models import Variable
from datetime import datetime, timedelta
from airflow import DAG

env = Variable.get("process_env")
namespace = Variable.get("namespace")

default_args = {
    'owner': 'airflow',
    'depends_on_past': False,
    'email_on_failure': False,
    'email_on_retry': False,
    'retries': 1,
    'retry_delay': timedelta(minutes=5)
}

##==============================##

## Définition du DAG
dag = DAG(
    'transfert-files-to-nexus',
    start_date=datetime.utcnow(),
    schedule_interval="0 2 * * *",
    default_args=default_args,
    max_active_runs=1
)
##=========================================================================================##

## Définition des tâches
start = DummyOperator(task_id='start', dag=dag)
end = DummyOperator(task_id='end', dag=dag)

transfertfile = KubernetesPodOperator(namespace=namespace,
                             task_id="transfertfile",
                             name="transfertfile",
                             image="registrygitlab.fr/docker-images/python-runner:1.8.22",
                             image_pull_secrets="registrygitlab-curie",
                             pod_template_file="/opt/bitnami/airflow/dags/git-airflow-dags/privileged_runner.yaml",
                             is_delete_operator_pod=False,
                             get_logs=True,
                             dag=dag)
                             
## Enchainement des tâches
start >> transfertfile >> end
```

**Anything else we need to know**:
I know that we have to use the ``KubernetesExecutor`` in order to have the **metadata**, but even if you use the ``KubernetesExecutor``, the fact that you have to use the **pod_template_file** for the ``KubernetesPodOperator`` makes no change, because in either ``LocalExecutor`` / ``KubernetesExecutor``you will endup with no pod name override correct & metadata.
kubernetes_tests/test_kubernetes_pod_operator_backcompat.py
security_context = {
            'securityContext': {
                'runAsUser': 1000,
            }
        }
        k = KubernetesPodOperator(
            namespace='default',
            image="ubuntu:16.04",
            cmds=["bash", "-cx"],
            arguments=["echo 10"],
            labels={"foo": "bar"},
            name="test",
            task_id="task",
            in_cluster=False,
            do_xcom_push=False,
            security_context=security_context,
        )
        context = create_context(k)
        k.execute(context)
        actual_pod = self.api_client.sanitize_for_serialization(k.pod)
        self.expected_pod['spec']['securityContext'] = security_context
        assert self.expected_pod == actual_pod
    def test_fs_group(self):