periodic job safe cleanup FRD
periodic job safe cleanup FRD

closes FOO-1204
flag=none

TEST PLAN:
  1) kill a periodic job so it is abandoned.
  2) force another abandoned job into the db with the same tag
     as the periodic cleanup job.
  3) periodic cleanup job will still run, and clear
     out it's previous phantom self.
Change-Id: I267a8beb567094ac27ec54d9760052871153d15b

Change-Id: Id3aa025bd2240d793bafd9a5fb1e06050fd9a51c
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/254606
Reviewed-by: Jacob Burroughs <8ecea6e385af5cf9f53123f5ca17fb5fd6a6d4b2@instructure.com>
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
QA-Review: Ethan Vizitei <73eeb0b2f65d05a906adf3b21ee1f9f5a2aa3c1c@instructure.com>
Product-Review: Ethan Vizitei <73eeb0b2f65d05a906adf3b21ee1f9f5a2aa3c1c@instructure.com>

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