Add the alternate bouncer as its own window

It needs to show above SysUI dialogs, so it can't
live in NotificationShadeWindowView (super_notification_shade.xml).

Since the alternate bouncer no longer lives in the
notification shade, touches to the alt bouncer are not considered
in the falsing algo, nor do touches keep the screen awake.
Therefore, we manually inform the powerManager of user gestures
like tap and swipe up on the alternate bouncer. However, we don't
count other swipes on the altBouncer (essentially "falsing") and
allow the device to sleep with its 10s keyguard timeout if no
valid touches on the altBouncer or fingerprint sensor occur.

Test: atest AlternateBouncerWindowViewModelTest
Bug: 327257758
Flag: ACONFIG com.android.systemui.device_entry_udfps_refactor TEAMFOOD
Change-Id: If7f2ec09fe53dd3dfe1b09847d92b1fdc2c6e81b