Refactor - Pull status bar "orchestration" logic out of CentralSurfaces

Also refactors the code to use flows where possible, and remove
unnecessary callbacks and broadcast receivers.

Test: StatusBarOrchestratorTest.kt
Test: CentralSurfacesImplTest.java
Test: Build and run with the flag disabled and enabled
Bug: 367592591
Flag: com.android.systemui.status_bar_simple_fragment
Change-Id: I7b3f916d6e6bc1000efddbca466113a6ebdf88bb