Customize Fingerprint enroll activities

Provide an interface for ODM/OEM to override Fingerprint enrollment
activities.

Bug: 364794493
Flag: EXEMPT can't apply flag for manifest change
Test: atest SettingsRoboTests:FingerprintEnrollTest

Change-Id: I9e5d904fc9382a9b5eff84a7f462e1a9c16c4ba0