[Expressive Design] Minor padding changes in screen layout

These changes fix :
1. Padding issue in Storage Dashboard list items
2. Make list group rounding symmetrical in App Storage Info page

BUG: 349670985
Test: manual
Flag: com.android.settingslib.widget.theme.flags.is_expressive_design_enabled
Change-Id: I1ceb3dd5459ead057cb79a9760232c4c8a90f249