Enforce log hints in neutron.services.metering

This change enforces log hints use and removes debug level log
translation, modifications are validated through a hacking rule.

Validate that hacking rules apply to directories:
    - neutron/services/metering

Change-Id: Ic763e81e8b06973013115af45c7c09a3e69c673b
Partial-bug: #1320867
Merge "Enforce log hints in neutron.services.metering"