`KubernetesPodOperator.name` randomization should be decoupled from the way the name is set. Currently `name` is only randomized if the `name` kwarg is used. However, one could also want name randomization when a name is set in a `pod_template_file` or `full_pod_spec`.

Move the name randomization feature behind a new feature flag, defaulted to True.

**Related Issues**

#14167 

tests/providers/cncf/kubernetes/operators/test_kubernetes_pod.py
}
                ]
            }
        }
        k = KubernetesPodOperator(
            namespace="default",
            image="ubuntu:16.04",
            cmds=["bash", "-cx"],
            arguments=["echo 10"],
            labels={"foo": "bar"},
            name=name_base,
            task_id="task",
            in_cluster=False,
            do_xcom_push=False,
            cluster_context="default",
            affinity=affinity,
        )
        pod = k.create_pod_request_obj()
        sanitized_pod = self.sanitize_for_serialization(pod)
        assert isinstance(pod.spec.affinity, k8s.V1Affinity)
        assert sanitized_pod["spec"]["affinity"] == affinity
        k8s_api_affinity = k8s.V1Affinity(
            node_affinity=k8s.V1NodeAffinity(
                preferred_during_scheduling_ignored_during_execution=[
                    k8s.V1PreferredSchedulingTerm(
                        weight=1,
                        preference=k8s.V1NodeSelectorTerm(
                            match_expressions=[
                                k8s.V1NodeSelectorRequirement(key="disktype", operator="In", values=["ssd"])
                            ]