Make 90 degree app launch less flaky

When apps are launched during a rotation there maybe a moment where the launcher is no longer visible and where the app also isn't visible. A Rotation Layer is shown instead to fill the gap. We now check for this layer.

Test: atest FlickerLibTests:OpenAppColdTest#appLayerReplacesLauncher

Bug: 209593837
Change-Id: Ic2810eed27f25398d4dc9748329729ea6213a9eb