Look into including the httpRequest property in logs

[zbjornson]

The v2 API supports a dedicated property (httpRequest) in addition to the payload that seems to improve readability in the console:

https://cloud.google.com/logging/docs/api/reference/rest/v2/LogEntry#httprequest

Not sure if we'd want to delete the properties occurring in the httpRequest from the payload, or let them remain redundant.

Depends on https://github.com/GoogleCloudPlatform/google-cloud-node/issues/1959