Improve defaulting to reloadable token in k8s so it shows correctly in config dump

[lahabana]

Kuma Version

master

Describe the bug

When running on k8s KUMA_DP_SERVER_AUTHN_ENABLE_RELOADABLE_TOKENS is always true however, on startup the config dump shows that it's off.

To Reproduce

No response

Expected behavior

No response

Additional context (optional)

On k8s we set this config to true always:

kuma/pkg/config/dp-server/config.go

Line 92 in 528ef07

EnableReloadableTokens bool `json:"enableReloadableTokens" envconfig:"kuma_dp_server_authn_enable_reloadable_tokens"`

We do it in:

kuma/pkg/xds/bootstrap/components.go

Line 21 in 528ef07

rt.Config().DpServer.Authn.EnableReloadableTokens || rt.Config().Store.Type == store.KubernetesStore,

This works but when we log the config:

kuma/app/kuma-cp/cmd/run.go

Lines 74 to 78 in c26b168

	cfgForDisplay, err := config.ConfigForDisplay(&cfg)
	if err != nil {
	runLog.Error(err, "unable to prepare config for display, log config will be empty")
	}
	runLog.Info("starting Control Plane", "version", kuma_version.Build.Version, "mode", cfg.Mode, "config", cfgForDisplay)

It shows as false as this is not done in the right place.
We should instead use PostProcess:

kuma/pkg/config/config.go

Line 8 in c3afa4a

PostProcess() error

which does the same but at a more suitable place:

kuma/pkg/config/loader.go

Line 100 in 310a1a3

return l.postProcess()