NIU Actions and Recents UI updates on Go

This tweaks the layout and fonts in the Go Overview. It also adds rounded corners to the task snapshots in the Recents view on Go by adding an overrideable value to the base Quickstep Launcher.

Bug: 186004471
Test: Manual (Pixel 3A)
Change-Id: I220836a95a6416b85bdb71d88822d25d939cf205