Replace 'import json' with oslo_serialization

Replace remaining occurences of 'import json' with
'from oslo_serialization import jsonutils as json'
so pylint doesn't complain every time someone happens
to make a change to one of the modules that still
uses it.

Change-Id: Ife9f0fc54ad36887bdb939028f8903be16e590d6
12 files changed
tree: 3708a7d7233a63b41dcf2a5a7d6e2c03bab61763
  1. neutron/