Merge branch '13146-shared-rails' refs #13146

Arvados-DCO-1.1-Signed-off-by: Peter Amstutz <pamstutz@veritasgenetics.com>

diff --cc services/api/app/controllers/application_controller.rb
Simple merge

diff --cc services/api/app/controllers/arvados/v1/groups_controller.rb
Simple merge

diff --cc services/api/test/functional/arvados/v1/groups_controller_test.rb
Simple merge