[remote-builder] This container appears to be completely broken

Affected builder image

`gcr.io/cloud-solutions-images/remote-builder:v0.3.1`

## Expected Behavior

Files are able to be copied to the remote builder host

## Actual Behavior

Files can not be copied to the remote host and the following error is returned:

```
scp: error: unexpected filename: .
```

## Steps to Reproduce the Problem

1. use any `cloudbuild.yaml` configuration with remote-builder

## Additional info

It appears that this broke when a security patch changed the way that scp behaves with the gcloud command. Relevant information here: https://superuser.com/questions/1403473/scp-error-unexpected-filename/1405020#1405020