Move padding rules for OutlineItemWidget from core to skins.

They relied on being after the OptionWidget padding rules in order
to override them, which stopped being true when the OptionWidget
rules were moved to skins.

We really, really shouldn't rely on inclusion order between
DIFFERENT WIDGETS for UIs to render correctly, but that's
a separate issue.

Bug: 63157
Change-Id: I33acc22fe80646e7d6168b60badafb6ef402db1d