Temporarily do not remove biometric view when animating to credential

When animating to device credential, the biometric view animates its
translation and opacity, then removes itself from the layout. Upon
removal, we currently remove all things from the handler. This includes
(racily) the callback to display device credential UI.

Thus, temporarily do not remove the view. Will fix this properly in a
follow-up CL.

Test: manual test with BiometricPromptDemo 10+ times
Test: atest com.android.systemui.biometrics
Bug: 143174046
Change-Id: Ibdf7c17514062a08ff3919fad2c798f9127e4234