Hide alternateBouncer onTrustChanges, not biometricAuth

The alternate bouncer can hide too early and not end up
running the dismiss action if hidden too early.

Test: atest StatusBarKeyguardViewManagerTest
Test: manually trigger trustGranted from the alternateBouncer
and see that the alternateBouncer dismisses on SFPS supported device
Bug: 289909028

Change-Id: Ibfea5aab7c7325e89c1c78e1566eed297adb22f7