servicepack v1.2.16 — service-manager tests stop synchronizing on sleep

Test files only; no framework behaviour changed.

TestServiceManager_Stop and TestServiceManager_Run each used a time.Sleep in
place of the condition they actually depended on, and both were load-bearing --
zeroing either fails the test. Under load they failed for reasons unrelated to
the code under test, surfacing as an unexplained flake in a consumer's CI.

Both now wait on the real condition. Consumers inherit the fix on their next
servicepack-update.