How to configure a non-default serviceAccount on a deployment

As you will need to specify 'podSpec' in Deployment as well, you should be able to configure the service account in the same way. Something like:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: my-deployment
spec:
  template:
    # Below is the podSpec.
    metadata:
      name: ...
    spec:
      serviceAccountName: build-robot
      automountServiceAccountToken: false
      ...