[BUG] Tenant selection drop-down should be disabled when custom tenant is disabled

[DarshitChanpura]

What is the bug?
When trying to switch tenants from Private to other, one of the radio button is to select from custom tenants. If the user doesn't have any tenant permissions, that radio button is grayed out, however the selector is still clickable. See the screen-shot:

How can one reproduce the bug?
Steps to reproduce the behavior:

1. Login as admin and create a new user, say user-x
2. Logout as admin and login as new user user-x.
3. Click on Switch Tenants
4. Click on the drop-down

What is the expected behavior?
Drop-down selector should not be clickable.

[derek-ho]

[Triage] @DarshitChanpura thanks for filing this issue! As you marked it, it looks like a good first issue we would gladly accept a PR for.