Document new collect_default_jvm_metrics flag for JMXFetch integrations

[gh123man]

What does this PR do?

Added docs for collect_default_jvm_metrics. This flag allows users to disable default jvm metrics in JMXFetch

Related PRs:
DataDog/datadog-agent#6923
DataDog/jmxfetch#345

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

[codecov]

Codecov Report

Merging #8153 (7c32c3d) into master (674adda) will decrease coverage by 7.03%.
The diff coverage is n/a.

Impacted Files	Coverage Δ
openmetrics/tests/conftest.py
cilium/tests/test_cilium.py
nginx/tests/utils.py
kubelet/tests/test_cadvisor.py
couchbase/datadog_checks/couchbase/__about__.py
...ller_manager/tests/test_kube_controller_manager.py
disk/tests/test_filter.py
coredns/tests/test_check.py
directory/datadog_checks/directory/directory.py
...re_iot_edge/datadog_checks/azure_iot_edge/types.py
... and 734 more

[apigirl]

docs look good

[coignetp]

LGTM!

[yzhan289]

Suggested change

	description: Allows disabling the collection of default JVM metrics
	description: Enables the collection of default JVM metrics

Small nit but feel like this wording would be more clear since it is disabled by default.

[gh123man]

Sorry if this was not clear! Actually this defaults to true. Perhaps I should call that out in the doc?
For context - the existing behavior is to collect default JVM metrics but I wanted to add a flag to explicitly disable that.

I thought it may be misleading to have a disable_collect_default_jvm_metrics: true because that logic feels backwards to me.

[ChristineTChen]

Is this option related to collect_default_metrics in the init_config?

integrations-core/datadog_checks_dev/datadog_checks/dev/tooling/templates/configuration/init_config/jmx.yaml

Lines 7 to 12 in b7221e2

	- name: collect_default_metrics
	required: true
	description: Whether or not the check should collect all default metrics.
	value:
	example: true
	type: boolean

[gh123man]

Is this option related to collect_default_metrics in the init_config?

integrations-core/datadog_checks_dev/datadog_checks/dev/tooling/templates/configuration/init_config/jmx.yaml

Lines 7 to 12 in b7221e2

	- name: collect_default_metrics
	required: true
	description: Whether or not the check should collect all default metrics.
	value:
	example: true
	type: boolean

Nope! This is a different behavior and it is specific to the instance.

[truthbk]

Just a comment regarding defaults and clarity.