Fix bug where we should not have changed when to log end of workspace binding in launche startup

In ag/25052869 we should only change when we end LAUNCHER_LATENCY_STARTUP_TOTAL_DURATION, but leave LAUNCHER_LATENCY_STARTUP_WORKSPACE_LOADER_SYNC/ASYNC unchanged.

Fix: 305243183
Test: lock screen, force stop launcher, verify COLD startup is logged before user unlocks screen
Flag: N/A
Change-Id: I206b7fcbe07fca99cdbcc3a53213550e6b8c7369