Prevent detached ST loggers from double cacheing

Since we support double detaches as a no-op, ensure that we only add a
detached STService event logger to the detached cache if it was
successfully removed from the active set.

Bug: 272147641
Fixes: 279855817
Test: Manual verification of dumpsys post-detach
Change-Id: I127e1a2c5d2570db828ce6db35d84000848b3502