Add tests for a desktop app opening from All Apps using KB

Adds a flicker and a functional tests. The scenario for it opens All
Apps using keyboard, searches for a specific app (calculator), chooses
it with arrow key and then launches with Enter.

Test: atest OpenAppFromAllAppsUsingKeyboardFlickerTest OpenAppFromAllAppsUsingKeyboardTest
Bug: 418234096
Flag: EXEMPT, not needed for e2e tests

Change-Id: I5410904586f6a18b13c17c1434fbdf9a6baec94e