allow api_ids on admin controller index

fixes CNVS-16807

test plan
 - account admin index should find user by sis_id

Change-Id: Idecb3b606e189c1e8f062498092357462efd4b90
Reviewed-on: https://gerrit.instructure.com/44163
Reviewed-by: Cody Cutrer <cody@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: August Thornton <august@instructure.com>
Product-Review: Rob Orton <rob@instructure.com>