Do not place elements if they are not going to be drawn anyways

This CL moves the location where we check whether an element should be
drawn from drawing time to placement time: there is no need to place
(and therefore compute the offset) of an element if we are not going to
draw it anyways.

Note that we still need to compute the size of an element in each scene
because the size of elements does impact the layout in both scenes the
element is in.

Bug: 308961608
Test: PlatformComposeSceneTransitionLayoutTests
Flag: N/A
Change-Id: Icaec9770dc06f0ee054541faea58052e193cc608