In MAILPOET-4464 we introduced the new state "valid_underprivileged".
During implementation we introduced the state for MSS key validation,
but we forgot about the premium key.
This commit adds support for the state also for premium key validation.
When the key is underprivileged we don't display any error.
We will add specific error for underprivileged keys with specific
access restrictions in follow-up commits.
[MAILPOET-5103]
bee18084c3