Fix the biometrics prompt talkback

Fix the duplicate talkback focuses on fingerprint icon and change the talkback message per Kerry's suggestion

Test: Manual - Open biometrics prompt and observe the duplicate focuses of decorative fingerprint icon has been removed and talkback announces the animation the same as the education during enrollment.
Fixes: 267407905

Change-Id: Ib2683cbf7a0ca409002b576a7bbcf1fe41808ca7