Don't override alpha for indication area

This was causing issues with visibility and fading. Indication
area should not apply its own logic and just use the default
from the keyguard_root_view model parent.

Also, don't send 0 values on dismiss to swipe, as it causes
a race condition on unlock.

Fixes: 325601893
Test: manual (its a binder change) so exercise top CUJs
Flag: ACONFIG com.android.systemui.migrate_clocks_to_blueprint
DEVELOPMENT
Flag: ACONFIG com.android.systemui.keyguard_bottom_area_refactor
TEAMFOOD

Change-Id: Ifab115b7792d2a6dfa5344e4352d713a680002cf