Load orientationWhenSet from disk

The field WallpaperData.mOrientationWhenSet is used by
WallpaperDataParser to store the legacy fields cropLeft, cropTop,
cropRight, cropBottom. If it is not reloaded after a reboot, these
legacy fields will not be stored, causing issues for backward B&R.

Flag: ACONFIG com.android.window.flags.multi_crop DEVELOPMENT
Bug: 329437172
Test: manually check the content of the backup after setting a wallpaper
Change-Id: Ic9babb33879cbdf9d035bf9af3ce2ab913940057