update pt-BR translation
update pt-BR translation

Change-Id: I5a25875fe0cfb0e0ac5cf7a75e98ec836e89e477
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/272678
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>

sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms