[Upgrade Assistant] Add permissions check for logs step

[alisonelizabeth]

The deprecations logs step in Upgrade Assistant requires users to have read access to.logs-deprecation.elasticsearch-default. While users using Upgrade Assistant will likely be a superuser, we should still add support to degrade gracefully in the case where someone who doesn't have the required index privileges tries to access UA.

I imagine we would show a warning callout under the logs step in the case where a user has insufficient privileges.

For inspiration, you can take a look at Snapshot & Restore, which checks for index privileges before rendering the "Restore" list. It uses the authorization utils from es_ui_shared.

[elasticmachine]

Pinging @elastic/kibana-stack-management (Team:Stack Management)