The "template_ext" mechanism is useful for automatically loading and jinja-processing files which are specified in parameters of Operators. However this might lead to certain problems for example (from slack conversation):

```
The templated_fields in  KubernetesPodOperator seems cause the error airflow jinja2.exceptions.TemplateNotFound when some character in the column, e.g / in env_vars.
The code got error.
env_vars=[
            k8s.V1EnvVar(
                name="GOOGLE_APPLICATION_CREDENTIALS",
                value="/var/secrets/google/service-account.json",
            ),
```

I believe the behaviour changed comparing to not-so-long-past. Some of the changes with processing parameters with jinja recursively caused this template behaviour to be applied also nested parameters like above.

There were also several discussions and user confusion with this behaviour: #15942, #16922

There are two ways we could improve the situation:
1) limit the "template_extension" resolution to only direct string kwargs passed to the operator (I think this is no brainer and we should do it)

2) propose some "escaping" mechanism, where you could either disable template_extension processing entirely or somehow mark the parameters that should not be treated as templates.

Here I have several proposals:

a) we could add "skip_template_ext_processing" or similar parameter in BaseOperator <- I do not like it as many operators rely on this behaviour for a good reason
b) we could add "template_ext" parameter in the operator that could override the original class-level-field <- I like this one a lot
c) we could add "disable_template_ext_pattern"  (str) parameter where we could specify list of regexp's where we could filter out only specific values <- this one will allow to disable template_ext much more "selectively" - only for certain parameters.


UPDATE: It only affects Kubenernetes Pod Operator due to it's recursive behaviour and should be fixed there.

airflow/providers/cncf/kubernetes/operators/kubernetes_pod.py
"""
        Monitors a pod to completion that was created by a previous KubernetesPodOperator
        :param launcher: pod launcher that will manage launching and monitoring pods
        :param pod: podspec used to find pod using k8s API
        :return:
        """
        try:
            (final_state, remote_pod, result) = launcher.monitor_pod(pod, get_logs=self.get_logs)
        finally:
            if self.is_delete_operator_pod:
                launcher.delete_pod(pod)
        if final_state != State.SUCCESS:
            if self.log_events_on_failure:
                for event in launcher.read_pod_events(pod).items:
                    self.log.error("Pod Event: %s - %s", event.reason, event.message)
            self.patch_already_checked(pod)
            raise AirflowException(f'Pod returned a failure: {final_state}')
        return final_state, remote_pod, result
    def on_kill(self) -> None:
        if self.pod:
            pod: k8s.V1Pod = self.pod
            namespace = pod.metadata.namespace
            name = pod.metadata.name
            kwargs = {}
            if self.termination_grace_period is not None:
                kwargs = {"grace_period_seconds": self.termination_grace_period}
            self.client.delete_namespaced_pod(name=name, namespace=namespace, **kwargs)