Most of the agent config files, except for the one used by OVN metadata
agent, does not contain the neutron_ prefix (metadata_agent.ini or
metering_atent.ini for example). The prefix is redundant because
the config files are usually created in the /etc/neutron directory.
Change-Id: Ibff6ab20e7309873cb7dd241264b4694646c52c1
0b0aafa062