Implement automatic retries for HTTP 409 errors from ImportOSLoginSSHKey #320
Description
We're constantly running into issues where we start two completely unrelated builds simultaneously, and one of them fails with the following error:
googlecompute.sc-rocky-baseimage: Checking image does not exist...
googlecompute.sc-rocky-baseimage: Creating temporary RSA SSH key for instance...
googlecompute.sc-rocky-baseimage: no persistent disk to create
googlecompute.sc-rocky-baseimage: Importing SSH public key for OSLogin...
googlecompute.sc-rocky-baseimage: Error importing SSH public key for OSLogin: googleapi: Error 409: Multiple concurrent mutations were attempted. Please retry the request.
googlecompute.sc-rocky-baseimage: Deleting SSH public key for OSLogin...
googlecompute.sc-rocky-baseimage: SSH public key for OSLogin has been deleted!
googlecompute.sc-rocky-baseimage' errored after 3 seconds 304 milliseconds: Error importing SSH public key for OSLogin: googleapi: Error 409: Multiple concurrent mutations were attempted. Please retry the request.
The code where the error originates is here: https://docs.cloud.google.com/go/docs/reference/cloud.google.com/go/oslogin/latest/apiv1#cloud_google_com_go_oslogin_apiv1_Client_ImportSshPublicKey
It would be preferable if Packer could retry the operation in these cases, since retrying the build will almost certainly make the error "go away". As far as I can tell the Go library used to interface with Google Cloud Platform doesn't support any retry mechanism though, so I'm not confident in trying to implement this myself.