1. Proposed title of this feature request: Support for GCE pd-balanced disk type

2. What is the nature and description of the request?: OpenShift installer and Machine API should support creation and management of compute resources with disk type "pd-balanced"

3. Why does the customer need this?

• pd-balanced are ssd disks with performances comparable to pd-ssd but with lower price

4. List any affected packages or components.

• Openshift Installer
• Openshift machine api