Description of the problem:

In OSD GCP wizard flow,  The widget "key ring" drop-down reported type error as below once user selected a key ring location under Encryption keys > Use custom KMS keys section.

The same works well with production and only seen with staging.

See detailed recordings in KeyringErrorStagingvsProd.mp4

Steps to reproduce:

1. Launch OCM Staging UI.
2. Open OSD wizard.
3. Select subscription as "Annual fixed capacity subscription" and Infrastructure type as "Customer cloud subscription"
4. Click "Next" and choose GCP cloud provider.
5. Proceed to "Next" step and  select "Use custom KMS keys" radio under "Advanced encryption" section.
6. Select "Key ring location" as global.
7. See the behavior.

Actual results:

At step 7, The widget "key ring" drop-down reported type error as above once user selected a key ring location 

Expected results:

 The widget "key ring" drop-down should list all available key ring if not respective valid error.