Combine UDFPS enroll segments into a single circle

Updates the UDFPS enrollment UI to present a single progress circle
instead of 4 segments (corresponding to the 4 underlying enrollment
stages). Visual progress is now continuous, based on the number of
remaining and total steps reported by FingerprintManager, rather than
being normalized across each stage.

As part of this change, the completion animation has also been changed
to display a checkmark rather than combining each of the segments into
a continuous circle at the end of enrollment.

Test: Manual

Fixes: 203134265
Change-Id: I1004c115a171deb14b579fa72ff00e951ca15f94