spec: fix flaky spec on user type spec
spec: fix flaky spec on user type spec

flaky spec failing on date comparision sometimes
when executed in loop by our test suite

example:

Types::UserType conversations has updatedAt field
for conversations and conversationParticipants
(./spec/graphql/types/user_type_spec.rb:336)
1 times with exception message:
  expected: "2021-04-26T17:55:05Z"
  got: "2021-04-26T17:55:06Z"

Edited to compare the parsed dates to avoid
fall into a milisecond difference that could
break the spec

fixes VICE-1115
flag=none

test plan:
  - Builds with no failure on Jenkins
  at this spec anymore from now

qa risk: low

Change-Id: Ic87f7b687d539e217fb554115b5e6942195c1884
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/263672
Reviewed-by: Caleb Guanzon <54fa1f30d451e4f3c341a8f3c47c9215fd0be9c6@instructure.com>
QA-Review: Caleb Guanzon <54fa1f30d451e4f3c341a8f3c47c9215fd0be9c6@instructure.com>
Product-Review: Caleb Guanzon <54fa1f30d451e4f3c341a8f3c47c9215fd0be9c6@instructure.com>
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>

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