Translate en.json in ar [Manual Sync] (#1286)

Sync of partially translated files: 
untranslated content is included with source language content

Co-authored-by: transifex-integration[bot] <43880903+transifex-integration[bot]@users.noreply.github.com>
Co-authored-by: Anna Iosif <anna.iosif@me.com>