Suggest removal of old `beta` keyword in storageclass.yaml

[redmcg]

This is an issue proposing a pull request (as requested in the Contributing guidelines) - but the PR is pretty simple.

In storageclass.yaml, the is-default-class annotation is still using the old beta variant:
storageclass.beta.kubernetes.io/is-default-class: "true"

The proposal it to remove the beta keyword.

[tstromberg]

Sounds great. Please open a PR at your leisure.

[keramiozsoy]

Hi I deleted , #4153

[redmcg]

I'll close this and follow #4153. Please re-open if the preference is to track via an issue as well as PR.