Pontoon: Update Japanese (ja) localization of AMO Frontend
Pontoon: Update Japanese (ja) localization of AMO Frontend

Localization authors:
- dskmori <ghoti.fish.dsk@gmail.com>

kumar303/addons-frontend,mozilla/addons-frontend,mozilla/addons-frontend,kumar303/addons-frontend,kumar303/addons-frontend,mozilla/addons-frontend,kumar303/addons-frontend,mozilla/addons-frontend