Test app-region CSS property when "window-controls-overlay" in display-override member

Description

This test validates that an element will drag the window around when running in "window-controls-overlay" mode.

Manual Test Steps:

1. Install this app, and toggle into "window-controls-overlay" mode.
2. Click and drag the blue rectangle containing the text "Drag Me". This element has the app-region:drag CSS property set.
3. If the app window moves around as you drag the blue rectangle, Click Here.