Allow users to schedule certificate updates (or set expiration date when running Update-AksHciCertificates)

After May 2022 release, users have 90 days to either upgrade their deployment or update their certificates with `Update-AksHciCertificates`

This is a drag to have to manually do, especially in environments where stability is paramount (not everyone wants to run the most bleeding edge version of Kubernetes). And from a Customer Support POV, I imagine a decent chunk of tickets come in with users having this issue?

If there is no plan to auto-rotate certs internally, then can we have a way to schedule the `Update-AksHciCertificates` command using Scheduled Tasks (or clustered scheduled tasks)?

Alternatively, can we have a flag on `Update-AksHciCertificates` to specify an expiration longer than 90 days?