App chip refactor

- Adds background outline replacing 2 circles + rect approach. This
enables easier shadow drawing code.
- Simplify structure of AppChipView.
- Adds an anchor View to simplify laying out of menu around app chip

Bug: 313644427
Bug: 317007147
Fix: 322760765
Flag: ACONFIG com.android.launcher3.enable_grid_only_overview TEAMFOOD
Flag: ACONFIG com.android.launcher3.enable_overview_icon_menu TEAMFOOD
Test: OverviewImageTest
Change-Id: I56c2644779863c083ae475a740a84321b1d0c396