NIU Actions: Support Dark Mode and Landscape

This adds light and dark color variants for the UI elements on the Go Recents screen. Toggling Dark Mode will switch between the themes. Additionally, the button spacing definitions have been updated to better support Landscape orientation.

Bug: 187866121
Bug: 183714277
Test: Manual (Pixel 3A)
Change-Id: Ia2c0cbf372882aad87e4018d10d8f85bd92842e0