Create separate classes that are responsible for applying window root view surface effects

The background surface was being blurred previously as part of the NotificationShadeDepthController
We need to do the same blurring as part of the transition to the primary bouncer.

Bug: 370555003
Flag: com.android.systemui.bouncer_ui_revamp
Test: verified manually
Test: added unit tests
Change-Id: I62a90882842322ecb8edc4e046c8fb40645758c9