Transfer the starting window to next running activity when invisible

Instead of checking to transfer the starting window every time an
activity becomes visible, this change attempts the transfer when
the top activity containing the starting window is becoming invisible.

Flag: com.android.window.flags.transfer_starting_window_to_next_when_invisible
Bug: 436461530
Test: atest ActivityRecordTests
Change-Id: I76cdfa8f4a9e7d2c320c5c2530f0ffdbc2876c84