Pontoon: Update Bengali (bn) localization of AMO Frontend
Pontoon: Update Bengali (bn) localization of AMO Frontend

Localization authors:
- Belayet Hossain <bellayet@gmail.com>
- Md. Nazmus Shakib <robin.labib@gmail.com>
- Ashikur Rahman <ashikurrahman068@gmail.com>
- MD. SHAYANUL HAQ SADI <sadi06888@gmail.com>

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