Connect shortcuts to transitionInteractor and clean up KeyguardPreviewRenderer

KeyguardPreviewRenderer doesn't need an actual KeyguardRootViewBinder or
KeyguardRootViewModel, as the RootView isn't modeled in wallpaperpicker,
only its elements are.

Additionally, connect the shortcuts to the transition interactor. This
fixes several situations where the shortcuts show when they shouldn't,
or vice versa.

Bug: 311689554
Fixes: 310211185
Test: atest KeyguardRootViewModelTest.kt
Flag: ACONFIG com.android.systemui.keyguard_bottom_area_refactor DEVELOPMENT
Change-Id: I3d111ba86e6227898fb55e6aada77fcd3f9d8663