Now oslo messaging notifier can use driver information from audit
middleware specific conf section. This allows audit to have different
driver and transport usage from existing standard oslo messaging
configuration. If audit middleware section is not defined, then existing
logic is used which identifies driver from shared common oslo messaging
notification conf section.
Adjusted code and tests to recent oslo messaging notifier topic to
topics arg change. And recent request.context change.
Change-Id: Ia9ce654d3903efd0fd7893347e44ee27a765c745
Closes-Bug: 1544840
c813c35214