Enforce log hints in neutron.services.l3_router

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/l3_router

Change-Id: I2a832c5e0c4ed2a944d199d6a2d6233b8cf838dd
Partial-bug: #1320867
Merge "Enforce log hints in neutron.services.l3_router"