WallpaperCropper: respect max wallpaper width

Some devices with high resolution screen only support 2048px wide
wallpaper (used to be fixed in I5b25bd931db0b2610e260921f28b92d8b0966aa6)

Pre-KitKat this works as follows:

- Launcher calls WallpaperManager.suggestDesiredDimensions and we
  limit the maximum size in that function
- The wallpaper setting application calls WallpaperManager
  .getDesiredMinimumWidth and respects that size

However, after KitKat, it is all broken because WallpaperCropper
now calculate its own dimension and does respect the value set by
getDesiredMinimumWidth (and it calls suggestDesiredDimensions,
which is supposed to be reserved for Launchers!)

Attempting to restore wallpaper setting by:

- Having WallpaperCropper respect config_wallpaperMaxWidth
- Having CMWallpaper (which copy pasted code from WallpaperCropper)
  respect getDesiredMinimumWidth
- For third party applications, if they respect getDesiredMinimumWidth,
  then they will work, but if they don't (i.e. uses WallpaperCropper's
  code), then there's nothing we can do.

Change-Id: Ib7da12a1c70befbeef2f305593d3841acbc45243