Skipped Flaky detection engine tests need re-enabled #71814
Description
There is no automated issue yet, as this has not failed on a tracked branch but we're seeing widespread failures for it on PR's.
detection engine api security and spaces enabled add_prepackaged_rules creating prepackaged rules should be possible to call the API twice and the second time the number of rules installed should be zero
There is also a related failure in alerts_detection_rules_prebuilt.spec.ts.
@andrew-goldstein encountered both these failures on his PR: https://kibana-ci.elastic.co/job/elastic+kibana+pipeline-pull-request/61797/flowGraphTable/