consolidate i18n strings in account reports

refs CNVS-13751

test plan
 - rake i18n:generate should not fail

Change-Id: I27ee88ba85b84a1e5d13c3993fcad8e1b5006ff4
Reviewed-on: https://gerrit.instructure.com/36834
Reviewed-by: Cody Cutrer <cody@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Rob Orton <rob@instructure.com>
QA-Review: Rob Orton <rob@instructure.com>