Correct conversions from microseconds to seconds

[xornivore]

What does this PR do?

Correct math in conversion from microseconds to seconds in a couple of places in kube_scheduler.

Motivation

Correct metric values.

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 #5354 into master will increase coverage by 3.03%.
The diff coverage is 90%.

Impacted Files	Coverage Δ
kube_scheduler/tests/test_kube_scheduler_1_13.py	100% <100%> (ø)	⬆️
kube_scheduler/tests/test_kube_scheduler_1_14.py	100% <100%> (ø)	⬆️
...er/datadog_checks/kube_scheduler/kube_scheduler.py	70.17% <50%> (ø)	⬆️
...ts/tooling/configuration/consumers/test_example.py
clickhouse/datadog_checks/clickhouse/utils.py
...checks_dev/tests/plugin/test_environment_runner.py
riakcs/datadog_checks/riakcs/riakcs.py
oracle/tests/test_oracle.py
...r/datadog_checks/openstack_controller/__about__.py
twistlock/datadog_checks/twistlock/twistlock.py
... and 856 more

[clamoriniere]

💯