Pontoon: Update Sinhala (si) localization of AMO
Pontoon: Update Sinhala (si) localization of AMO

Co-authored-by: හෙළබස සමූහය (HelaBasa Group) <b9ffe367efdf35a5e502b4e19d7d8d74a75e4ac7@yalu.lk>

diox/olympia,mozilla/addons-server,mozilla/addons-server,diox/olympia,mozilla/addons-server,diox/olympia,mozilla/addons-server,diox/olympia,wagnerand/addons-server,wagnerand/addons-server,wagnerand/addons-server,wagnerand/addons-server