Image pull fails as rejected by policy in OpenShift 4

Issue

• When trying to deploy a container image, the deployment fails with ImagePullBackOff and the following error message:

  Failed to pull image "registry.example.com:5000/my-project/myimage@sha256:c7be7ee7e61afee1618c09271db59f846aa5a9e17487f909793cef5f722303c0": rpc error: code = Unknown desc = Source image rejected: Running image docker://registry.example.com:5000/my-project/myimage@sha256:c7be7ee7e61afee1618c09271db59f846aa5a9e17487f909793cef5f722303c0 is rejected by policy.
  

• When trying to deploy a container image, the deployment fails with ImagePullBackOff and the following error message is observed:

  Failed to pull image "example.com/my-image/my-image@sha256:xxxxxxx": rpc error: code = Unknown desc = SignatureValidationFailed: copying system image from manifest list: Source image rejected: Running image docker://example.com/my-image/my-image@sha256:xxxxxxx is rejected by policy.