Reset view flipper alpha to 1.

I've seen insteances of the inset animation setting the view flipper
alpha to 0 where end is never called and the alpha never gets reset to
1. When we start the appear animation, we want to ensure that the view
flipper alpha is set to 1.

Fixes: 261730718
Test: Open and close bouncer in password and then change security method
to pattern and open and close bouncer.

Change-Id: I69deffb7f9828ecbe851b8feb8335a9b1fd87499
(cherry picked from commit f5336a189f9b523d28d3ed48a1ab72e6b8d4b2df)
Merged-In: I69deffb7f9828ecbe851b8feb8335a9b1fd87499
(cherry picked from commit df7c6596c7973c8bc4c6a09d78256f6126d1793c)
Merged-In: I69deffb7f9828ecbe851b8feb8335a9b1fd87499