Add sleep to be able to test labeling service dashboard

[vbrodsky]

Description

Since creation of labeling dashboard in ES is totally asynch, the only way to test it at all is to add some sleep time

In my observation 5s is enough for a labeling service to be created in ES and failure of this test would indicate either a coding or an environment or a performance issue

PS Did not see any other way to keep this test and prevent it from being 'flaky'

Fixes # (issue)

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