Optimize generate sessionless launch endpoint
Optimize generate sessionless launch endpoint

Fixes: PLAT-1989

Test Plan:
- Make sure optimizations did not break any previous
  functionality.

Change-Id: Ibae40acc8d6b1e69ab4ee3166b4b0ca655664e21
Reviewed-on: https://gerrit.instructure.com/95817
Tested-by: Jenkins
Reviewed-by: Nathan Mills <10b0771d20c18ad0d98c1d000665e443052b40b0@instructure.com>
QA-Review: August Thornton <9adc7a1161ddf32ff608de792a7e50179545f026@instructure.com>
Product-Review: Weston Dransfield <e9203059795dc94e28a8831c65eb7869e818825e@instructure.com>

djbender/canvas-lms,venturehive/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,SwinburneOnline/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,grahamb/canvas-lms,grahamb/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,grahamb/canvas-lms,venturehive/canvas-lms,SwinburneOnline/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,grahamb/canvas-lms