Update logs config service field to optional

[ChristineTChen]

What does this PR do?

This PR makes:

• logs config service optional
• sync integration configs
• update logs check template

Motivation

By default, the service should be the one in init_config/instance level.

Additional Notes

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have changelog/ and integration/ labels attached

[hithwen]

the config templates tests need fixing as they have some hardcoded examples

[hithwen]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[codecov]

Codecov Report

Merging #7209 into master will decrease coverage by 8.75%.
The diff coverage is n/a.

Impacted Files	Coverage Δ
...ts/tooling/configuration/consumers/test_example.py	100.00% <ø> (ø)
datadog_checks_dev/tests/test_docker.py	48.14% <0.00%> (-51.86%)	⬇️
datadog_checks_dev/tests/tooling/test_utils.py	73.40% <0.00%> (-26.60%)	⬇️
datadog_checks_dev/datadog_checks/dev/env.py	22.72% <0.00%> (-20.46%)	⬇️
datadog_checks_dev/datadog_checks/dev/warn.py	63.63% <0.00%> (-18.19%)	⬇️
...atadog_checks_dev/datadog_checks/dev/structures.py	68.85% <0.00%> (-18.04%)	⬇️
datadog_checks_dev/tests/test_conditions.py	82.25% <0.00%> (-17.75%)	⬇️
datadog_checks_dev/datadog_checks/dev/docker.py	24.81% <0.00%> (-17.30%)	⬇️
datadog_checks_dev/datadog_checks/dev/_env.py	53.24% <0.00%> (-9.10%)	⬇️
...atadog_checks_dev/datadog_checks/dev/subprocess.py	72.97% <0.00%> (-5.41%)	⬇️
... and 736 more