Fix incorrect QS paddings after relayout

Margin and padding calculation should actually be part of the layout
pass, such as it cannot be out of sync.

Test: pull down QS with Media on LS, split shade, launcher
Test: atest QSSquishinessControllerTest
Fixes: 204517562
Change-Id: I0001502f7c3368060e7b8fc93c753b05a8386aa6