[System benchmark] Start service in SetUp process to update placeholders in config

[mrodm]

Fixes #2905

In order to be able to update the placeholders like Hostname and Port with the expected values, the service must be started in the SetUp method so it can update the variables in the configuration using those placeholders accordingly.

This PR ensures that the service is setup when the configuration is read and therefore policy variables are also set.

Example of error using elastic-package version v0.117.1:

Error: error running package system benchmarks: could not set up benchmark runner: could not create package policy (req {"name":"","description":"","namespace":"ep","policy_id":"a9024eda-09b5-4da0-a4e5-1e485f77c7cf","package":{"name":"sentinel_one","version":"2.0.0"},"inputs":{"sentinel_one-cel":{"enabled":false},"sentinel_one-httpjson":{"enabled":true,"vars":{"api_token":"xxxx","enable_request_tracer":true,"url":"http://:0"},"streams":{"sentinel_one.activity":{"enabled":true,"vars":{"preserve_original_event":true}}}}},"force":true}); API status code = 400; response body = {"statusCode":400,"error":"Bad Request","message":"Package policy is invalid: inputs.httpjson.vars.url: ["Invalid URL format"]"}

where the url is not rendering the variables ("url":"http://:0").

Including the fix in this PR:

Author's Checklist

• Review system benchmark docs
• Run system benchmarks and compare with previous implementation.

[mrodm]

/test

[mrodm]

/test

[elasticmachine]

💚 Build Succeeded

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• Commit: e6ea4bc

History

• 💔 Build #6790 failed c0973e4
• 💔 Build #6789 failed c0973e4
• 💛 Build #6788 was flaky 1a27d21
• 💚 Build #6776 succeeded e22049f

cc @mrodm

[mrodm]

@navnit-elastic could you test the changes in this PR to validate it works with the system benchmark you were working on in #2905 ?
Thanks!