Description of problem:

In ROSA Hypershift cluster wizard > Under machine pool step, The validation message against the private subnet name field shown as "Subnet ID is required" but with current change , it should be replaced with "Subnet Name is required"  or "Subnet is required" as user only select the private subnet by referring name.

See below snapshot

Steps to reproduce:

1. Launch OCM UI staging
2. Open ROSA Hypershift wizard.
3. Reach to machine pool step after filling required values in each step.
4. Select VPC and select the private subnet names for machine pool.
5. Select a different VPC and see the field validation message

Actual results:

Field validation message shown as "Subnet ID is required" but the user has chosen always subnet via subnet name currently. This would confuse user.

Expected results:

Field validation message should be replaced to "Subnet Name is required" or simply "Subnet is required" to get more clarity from the wizard side.