fix ContextExternalTool sync_placement function to not use stale data
fix ContextExternalTool sync_placement function to not use stale data

Change-Id: I74d01748b9e46e7974c55db5afd8fa62864f4d80
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/267365
Reviewed-by: Stephen Kacsmark <90aaf30f5583a54f0f3cdbd115e37bda3a251932@instructure.com>
QA-Review: Stephen Kacsmark <90aaf30f5583a54f0f3cdbd115e37bda3a251932@instructure.com>
Product-Review: Stephen Kacsmark <90aaf30f5583a54f0f3cdbd115e37bda3a251932@instructure.com>
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>

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