`skaffold fix` erroring when using on a a skaffold.yaml using the gcb builder - ex:`examples/google-cloud-build`

Currently I am attempting to migrate the `examples/` directory to v3alpha1 (from v2beta28). In attempting this for `examples/google-cloud-build` I get the following error and am unable to migrate it directly to v3alpha1:
```
aprindle@aprindle ~/skaffold/examples/google-cloud-build [fix-7543/update-all-examples]$ skaffold fix -o skaffold.yaml
validating upgraded config: source: skaffold.yaml, in unnamed config[0]: found a '' artifact, which is incompatible with the 'gcb' builder:

image: skaffold-example

To use the '' builder, remove the 'googleCloudBuild' stanza from the 'build' section of your configuration. For information, see https://skaffold.dev/docs/pipeline-stages/builders/
source: skaffold.yaml, in unnamed config[0]: found a '' artifact, which is incompatible with the 'gcb' builder:

image: skaffold-example

To use the '' builder, remove the 'googleCloudBuild' stanza from the 'build' section of your configuration. For information, see https://skaffold.dev/docs/pipeline-stages/builders/
```