Separate AOD shelf from status view

Create a new section for the aod shelf, and align it in different
locations based on split shade. Also use a placeholder view in order
to get proper sizes for NSSL.

Bug: 288242803
Fixes: 288237177
Test: atest SystemUITests
Test: all migration flags off/on

Change-Id: Ic0438db1f60e34908c7db56f4cc4b8f6f444be4a