Description of the issue

In ROSA Hypershift wizard, the user has configured multiple machine pools . In couple of machine pool definition user has chosen different private subnets from the same region. During the submission of the cluster definition, the backend error thrown and user has failed to create the cluster. This is wrong.  Couple thoughts are

• Are we restricting the user from creating machine pools with different subnet definition belongs to the same availability zone as part of day 1 action?
• If this is a limitation then user must be warned or restricted from doing it (i.e. configuring machine pool definition with private subnet belongs to same AZ) from wizard side.

See the screenshot

Steps to Reproduce:

1. Launch OCM UI staging.
2. Open ROSA Wizard > Hypershift flow (control plane as Hosted).
3. Reach to machine pool step.
4. Select a VPC that has multiple private subnets including more than one private subnets from same AZ).
5. Add few machine pool definition with private subnets from different AZ.
6. Add couple of machine pool definition with private subnets belongs to same AZ
7. Click "Next" steps and reach to "Review and create" page.
8. Click "Create cluster" and see the behavior.

Actual results:

Cluster creation with fails from UI with above mentioned error when multiple machine pool definition with private subnet belongs to same AZ.
The error message itself doesn't give a clarity about the reason for the failure and the way it handled from UI wizard itself needs to be improved.

Expected results:
Cluster creation should be successful but in case creation of a HCP Cluster  with multiple machine pool definition using different private subnet belongs to same AZ is a limitation then we should warn or restrict the user in machine pool step.