chore: Translate transifex_input.json in pt_BR

99% of minimum 50% translated source file: 'transifex_input.json'
on 'pt_BR'.

Sync of partially translated files: 
untranslated content is included with an empty translation 
or source language content depending on file format

translations/frontend-app-course-authoring/src/i18n/messages/pt_BR.json

@@ -441,6 +441,9 @@
   "course-authoring.course-team.warning-modal.button.return": "Retornar à listagem do grupo",
   "course-authoring.course-unit.add.component.title": "Adicionar um novo componente",
   "course-authoring.course-unit.add.component.button.text": "Adicionar componente:",
+  "course-authoring.course-unit.modal.button.text": "Selecionar",
+  "course-authoring.course-unit.modal.container.title": "Add {componentTitle} component",
+  "course-authoring.course-unit.modal.container.cancel.button.text": "Cancelar",
   "course-authoring.course-unit.heading.icon.chevron.alt": "Alternar menu suspenso",
   "course-authoring.course-unit.heading.breadcrumbs.loading": "Carregando...",
   "course-authoring.course-unit.prev-btn-text": "Anterior",