Maintain fixed-rotation illusion for wallpapers in transition

Wallpaper tokens, like activities, can be nested in a fixed
rotation leash to abstract it away from shell. So, this adds
the same logic as used for activity to the wallpapertoken.

Additionally, shell only receives the rotation-leash, so it
can't modify the token's visibility -- so this also ensures
that the token is made visible.

Bug: 349966512
Flag: com.android.window.flags.ensure_wallpaper_in_transitions
Test: close any fixed-rotation task into launcher.
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:27127fb6f00d48b1500d01112e6c217cca6f7678)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:c383f54cb454372f8da04ecb5d6c6796d5435a3f)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:40de33574315babbbec9236dd0ae713880dc6def)
Merged-In: Ic745390edf25ef2e5f7172a8cc4e1dde09875514
Change-Id: Ic745390edf25ef2e5f7172a8cc4e1dde09875514