loadtest: check the /v4/system/ping endpoint instead of sleeping for 30 seconds

Description

Right now, after the provisioning is complete, there is a hardcoded sleep of 30 seconds which is an approximate time needed for mattermost to take all the peers in the cluster and really start serving requests.

Instead of sleeping, we should ping the status endpoint and check the response to verify whether it is up or not.

QA Test Steps

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Mana

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Assignee

Unassigned

QA Assignee

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Reporter

Agniva De Sarker

Epic Link

Fix versions

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Mattermost Team

Platform

Sprint

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