Reset fingerprint lockout upon successful unlock

FingerprintSettings should not start listening for fingerprints until
after Pin/Pattern/Pass is entered

Fixes: 63437524
Fixes: 63739006

Test: open FP settings, touch an invalid finger 5 times
close FP settings, re-enter FP settings, enter Pin/Pattern/Pass
touch FP with valid finger, should not be in lockout mode

Change-Id: I9b322248b30f3c4f49414e5bc0693f03a8f2dbe4