gcloud crashed (TypeError): a bytes-like object is required, not 'str'

Got a few Docker-related errors when running Dataflow tests on my Mac. I assume the root cause has something to do with the warning about Docker client versions above 18.03 (I am on Docker 18.09.1), but not sure.

{{\> Task :runners:google-cloud-dataflow-java:buildAndPushDockerContainer FAILED
WARNING: `gcloud docker` will not be supported for Docker client versions above 18.03.

As an alternative, use `gcloud auth configure-docker` to configure `docker` to
use `gcloud` as a credential helper, then use `docker` as you would for non-GCR
registries, e.g. `docker pull gcr.io/project-id/my-image`. Add
`\--verbosity=error` to silence this warning: `gcloud docker
\--verbosity=error \-- pull gcr.io/project-id/my-image`.

See: https://cloud.google.com/container-registry/docs/support/deprecation-notices#gcloud-docker

ERROR: gcloud crashed (TypeError): a bytes-like object is required, not 'str'

If you would like to report this issue, please run the following command:
gcloud feedback

To check gcloud for common problems, please run the following command:
gcloud info \--run-diagnostics

\> Task :runners:google-cloud-dataflow-java:cleanUpDockerImages
Untagged: us.gcr.io/apache-beam-testing/java-postcommit-it/java:20201124131024
ERROR: (gcloud.container.images.delete) [us.gcr.io/apache-beam-testing/java-postcommit-it/java:20201124131024] is not a valid name. Expected tag in the form "base:tag" or "tag" or digest in the form "sha256:"}}

Imported from Jira [BEAM-11340](https://issues.apache.org/jira/browse/BEAM-11340). Original Jira may contain additional context.
Reported by: ibzib.