Show Choose/ConfirmLock before showing BiometricEnrollIntroduction

Skip button is now shown when ChooseLock is launched by
BiometricEnroll, otherwise users are forced to use passwords
(maybe good thing?)

Bug: 111548033

Test: Pin/pattern/pass must be set/confirmed before enrollment
Test: Able to enroll FP in SUW and Settings

Change-Id: Ic4bbeb539e4bf01c1c402dec308943292b43406d