Description of problem:
"Overcommitted"

Version-Release number of selected component (if applicable):
4.14

How reproducible:
Always

Steps to Reproduce:
1. In 4.14, create Vm from volume / with instanceType.
2. In the create wizard, step 2, select "Overcommitted"
3.

Actual results:
"Overcommitted" instanceType is shown.
This could be misleading.

Expected results:
"Overcommitted" instanceType is not shown.

Additional info:
I'd suggest that we only introduce this instance type