Add tests for Meta+Tab Overview toggle feature

Adds flicker and functional tests. The scenario opens a desktop and a
fullscreen apps, opens Overview, switches focus to another app using
arrow keys and launches the focused app using Meta+Tab.

Test: atest ActionTabSwitchToDesktopAppFlickerTest
Bug: 418229635
Flag: EXEMPT not needed for e2e tests
Change-Id: I719512c4deea79b8d6df99f61ea9762c21066185