Hitting Docker image pull limits

**Describe the bug**
Need to set base images to ECR public URIs so we aren't accessing Dockerhub in Prow.

**Steps to reproduce**

**Expected outcome**
A concise description of what you expected to happen.

**Environment**

* Kubernetes version
* Using EKS (yes/no), if so version? 
* AWS service targeted (S3, RDS, etc.)
