AutoUserNames doesn't work in TestCoverage.Manager but does in %UnitTest.Manager

[isc-tleavitt]

Internal ref / backstory: APPS-29412

Fix: Call ##super() from overridden callbacks from %UnitTest.Manager

OnBeforeTestCase/OnAfterTestCase are the real missing cases, but we should call ##super() from any other overridden On* callbacks just to future-proof.