Extract StartingSurface interface on WMShellBaseModule(7/N)

Decouple the dependency for the rest CLs.

Bug: 73289295
Bug: 131311659
Test: atest WindowOrganizerTests StartingSurfaceDrawerTests
SplashscreenTests

Change-Id: Ifd323714184fad285b4d65f8c86c9b8feafc2374
12 files changed