Defer resuming when creating home stack for starting home

This avoids starting home activity recursively.
Also resume home if the display is empty.

Bug: 144281234
Bug: 144345635
Test: Force-stop home while only home activity exists
Test: atest MultiDisplaySystemDecorationTests#testLaunchSecondaryHomeActivityOnDisplayWithDecorations
Change-Id: I907c3153bddada178fce5d785c3ed7f5624c515c