[pinpoint] Add a retry for taskqueue.add().
[pinpoint] Add a retry for taskqueue.add().

Bug: catapult:#3931
Change-Id: I97820779974ff6d9893b412ef1db7e0c801777cd
Reviewed-on: https://chromium-review.googlesource.com/689958
Reviewed-by: Juan Antonio Navarro Pérez <1649bb5e6b9eafe026580e338065dc64ba6b80b2@chromium.org>
Reviewed-by: Annie Sullivan <259f984aa3b2892f452a20facda15d22b94ee4f8@chromium.org>
Reviewed-by: Simon Hatch <490a224d89645d3fea983d7189ce51bde0a00c1d@chromium.org>
Commit-Queue: David Tu <baa605d781958521249fdcf7bad76b01d943134a@chromium.org>

catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult