Update realtime assignee e2e spec waits

What does this MR do?

Removes the 120 second wait for checking the assignees widget to get a better idea if this issue is fixed: #293699 (comment 582128695)

Also adds a 1 second sleep as suggested here to prevent race conditions.

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

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Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
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