Attempt to remove the starting window when an activity becomes invisible.

The starting data can be associated with the task and shared between
activities. If a trampoline activity, which never draws and gets
destroyed right after being launched/does not own the starting
data, the starting window cannot being removed from it. Turns out may be
miss opportunity to remove the starting window after trampoline gone.
Therefore, to be more generic, an attempt can be made to remove the
starting window whenever an activity becomes invisible.

Flag: com.android.window.flags.ensure_starting_window_remove_from_task
Bug: 405253899
Test: atest ActivityRecordTests
Change-Id: Iba7118b793ed55b0e85e0d21f2419dfead84759d