Fix CloseAllAppWithAppHeaderExit tests

- Fix the filtering so that close app transition doesn't pick up the
transition from closing the last app.

- Fix CLOSE_LAST_APP scenario as it doesn't pick up the before state of
the transition.

- Add desktop wallpaper as a component so we can do assertions on it.

Bug: 343879388
Flag: EXEMPT Bugfix in test
Test: Manual

Change-Id: I3e1e57587396a041138e4d0c00f0ab08b5798bbf