Simplify common configuration for k8s app auto-discovery

[nklaassen]

What would you like Teleport to do?

When using auto-discovery for Kubernetes applications https://goteleport.com/docs/auto-discovery/kubernetes-applications/, it would be nice to be able to configure common options that would apply to all apps by default, instead of requiring annotations on every single service.

What problem does this solve?

For customers with many okta groups, it's common to limit the JWT size with a rewrite: { jwt_claims: none } option. Currently this would require setting a k8s annotation on every discovered service.

Since VNet will initially be supporting TCP app access only, it would also be nice to be able to configure TCP as the protocol for many discovered apps without requiring annotations on each one.

If a workaround exists, please include it.

set annotations on every single service