[sb] Basic compose replacement of the fragment

This CL sets up the minimum amount of scaffolding to hook up the
existing PhoneStatusBarView (+ its controller) to the status bar window,
wihtout the use of the CollapsedStatusBarFragment.

There are still some broken things (like event animations), but the
general idea is sound. It also has the advantage of making clear the
list of things that we need to modernize; anything that doesn't look
like native Compose (like setting up icon controllers) needs to be
turned into modernized architecture.

Test: StatusBarInitializerTest
Bug: 364360986
Flag: com.android.systemui.status_bar_simple_fragment
Change-Id: I1f6301f94adbddc8a35599a27a6fd41d5d07ad20