Complete DisabledWallpaperManager's stub APIs.

DisabledWallpaperManager is used to guard against inappropriate access
to wallpaper APIs in case the caller didn't check for support using
WallpaperManager#isWallpaperSupported.  New APIs have been added to
WallpaperManager but corresponding stubs were not added to
DisabledWallpaperManager, leading to unguarded crashes.  This CL
completes the stubs and re-arranges the stubs in the order of their
declaration for readability.

Bug: 355307617
Test: Future proofing an unlikely path.  Everything still works.
Flag: EXEMPT bugfix
Change-Id: I40cbe107fb87c6e5cf10550489eaffefc7b66503