Revert "Reland "Prevent dismissing starting window when reopening app""

This reverts commit be71ed8a.

Causes various issues. Out of time for Q to investigate and fix.

Fixes: 135706138
Fixes: 135661232
Fixes: 135976008
Fixes: 135921478
Fixes: 135780312

Bug: 134561008
Change-Id: Ifb7b1fe2b189649d320516e70368625c903debea