When enabling the OctaviaForwardAllLogs option, the amphora-agent
forwards all the logs to the rsyslog container. So rsyslog should accept
every incoming messages from the amphora and record them in
octavia-amphora.log (this configuration is similar to the rsyslog
configuration in the Octavia devstack plugin).
Change-Id: I63d64ebe7ea2f4cd8eeb09f256870dfd2e4c1e92
Closes-Bug: #1906414