Only request resetLockout if enrollments exist

If a race condition occurs, at least we limit it to when enrollments
exists. After this fix, at least when users exit settings and
re-enter face settings, things should work again

Bug: 183906260
Test: enroll, exit settings, enter face settings, enroll
Change-Id: I6d5ebf2d19eda43b8efe589d96c3bcc216078f48