Description of problem:
Refresh ARN functionality removes already selected ARN values from the role fields. Once the user made selections for the installer ,worker,support roles and clicks on the "Refresh ARN" then the selected values are replaced with other ARN values in the list. This seems wrong. 

How reproducible:

 Always

Steps to reproduce:

1. Launch OCM UI staging.
2. Open ROSA wizard.
3. Select control plane as Standalone/Hosted
4. Go to next step.
5. Select installer ARN (managed/non-managed for ROSA) and other roles ARNs.
6. Click on refresh ARN button.
7. See the ARN field values.

Actual results:
In Step 7, After clicking refresh ARN button, the previously selected the ARN field values (in Step 5) are replaced with other values.

Expected results:
In Step 7, The ** ARN field values should stay as it is after clicking "Refresh ARN" button. 
**