locksettings: only log profile key removal when actually done

The message "Remove keystore profile key for user" is always being
logged at INFO level when a user's locksettings state is removed.
However, that step is only applicable for profiles, so usually it's
irrelevant and is a no-op.

It could serve as a hint that the user's locksettings state is being
removed.  However, there's already a proper log message for that.

So, let's first check whether the user actually has a profile key,
before attempting to remove it and logging that removal.

Bug: 268526331
Change-Id: I90f46bc4cf5bfe096b0b037c5b88a9a9be2dcdd6
Merged-In: I90f46bc4cf5bfe096b0b037c5b88a9a9be2dcdd6
(cherry picked from commit deb0af00)