Add vertical and horizontal dividers for large cards of homepage

- Add a new field in ContextualCard to store whether this card is a large one
- Set dividers for large cards in renderer

Fixes: 119528161
Fixes: 119641839
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.homepage
Change-Id: I5cb95214789f44ccfd8d9ce2177ca2b84835b7a4