This would make `LockScreenHandle` as an instance-able function. Currently it's just a singleton component like LockScreen. And because we don't need to instance multiple `LockScreenHandle`, making it instance-able seems unnecessary.

However, due to the need of testing, I would try to fix this with similar tricks in C++ singleton to prevent it can be instanced more than once. If I fail at this, I would at least add a caveat in comment to mark this decision clearly.