Screenshots broken for activities with dialog themes

Makes progress towards fixing screenshots and transitions
for non-fullscreen activities.

Partially reverts I48053f551ed1c118764aa30e0b6408db64d4a5f1 and
applies it in a way that does not break screenshots in general.

Note that screenshots of non-fullscreen activities are still somewhat
broken because their insets can currently not be calculated correctly.

Bug: 72757033
Test: Open dialog activity, go to recents, verify it has a reasonable screenshot and smooth transition
Test: Open letterboxed activity, go to recents, verify it has a reasonable screenshot and smooth transition
Change-Id: Ica4d88370df00a91724d59b2cad6b27826beba04