Add user-supplied arguments in log_handler

Sync from Oslo, change-id: I91289cc4a60f5dab89bca852e6f52b4b83831e47

When using PublishErrorsHandler, it will missing user-supplied
arguments. For example, do LOG.info("blabla %s", "foo"), the
payload only contains "blabla %s", but we expect it like "blabla foo".

Change-Id: I9e5515da31a04b82d49e406bc6b246f940fb73fc
Merge "Add user-supplied arguments in log_handler"