[Alerting UI] Alert flyout doesn't have any information if alert type is not available for the current user role, just Save button is disabled.

[YulNaumenko]

Currently user doesn't have any UI information that alert type is not allowed from Management UI for the user with disabled

Steps to reproduce:

1. Login as user with no Stack Monitoring access.
2. Navigate to Alerting management ui and open create alert flyout.
3. Fill top section with name and schedule.
4. Select CPU usage alert type (no fields to populate is required).
5. Add ServerLog action.

Observer that Save button is disabled, but no warnings or errors is displayed:

If user have Stack Monitoring access CPU Usage alert type fields is available and form is valid:

We should provide some user info about not available alert types. At least show why Save button is disabled.

[elasticmachine]

Pinging @elastic/kibana-alerting-services (Team:Alerting Services)

[pmuellr]

Ideally we wouldn't let customers get this far into the UI, for alert types that aren't enabled via RBAC.

Seems like we should present these as "disabled" in the alert type picker - but then we may have multiple reasons to disable - eg, gold+ actions when running with basic vs alert type not enabled due to RBAC. We'll need to provide some kind of visual cue for the "reason" - even if it's just hover, but that feels not great. Perhaps some "badge" we can add to the icons indicating why it's disabled?

[mikecote]

@YulNaumenko mentioned this relates to #75414.

[YulNaumenko]

Closed this in #77097