Use WallpaperDescription crops for static wallpapers

We have two ways to set static wallpapers with crop hints: one takes
crop hints as one or two arguments, and the other takes a
WallpaperDescription. Before this change, the description methods just
used the crop hints in the description and passed them to the crop hints
methods. The change makes the WallpaperDescription methods the main
ones, with the crop hint methods creating a WallpaperDescription and
calling them.

This is the first step to setting static wallpapers with
WallpaperDescription and storing the description on the framework side.

Bug: 380245309
Bug: 395679036
Flag: EXEMPT refactor
Test: CTS tests
Test: manually verified cropping behavior
Change-Id: If1352733d9da0fe7d63dca3a2f45a852606e29e3