spec: Skip flakey RCE spec
spec: Skip flakey RCE spec

flag=none

This behavior is covered decently in unit tests, but we
should still have an integration-style test to cover it.

MAT-386 is to fix the flakiness of the spec or test the
behavior in a better way.

Test Plan:
specs pass

Change-Id: I1500537b73831166da1bf8a156b763e58764def8
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/271310
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Reviewed-by: Andrea Cirulli <b4e55ef5ee4bae8ad31f7c81009bfc0af1714a1f@instructure.com>
QA-Review: Weston Dransfield <e9203059795dc94e28a8831c65eb7869e818825e@instructure.com>
Product-Review: Weston Dransfield <e9203059795dc94e28a8831c65eb7869e818825e@instructure.com>

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