Enable @PortraitLandscape for testBackground

Now that Recents rotation crash is fixed

Change-Id: Ibca9460e45fc533e414537f7923a2d09fc59f58a

quickstep/tests/src/com/android/quickstep/TaplTestsQuickstep.java

@@ -208,7 +208,7 @@ public class TaplTestsQuickstep extends AbstractQuickStepTest {
 
     @Test
     @NavigationModeSwitch
-//    @PortraitLandscape
+    @PortraitLandscape
     public void testBackground() throws Exception {
         startAppFast(resolveSystemApp(Intent.CATEGORY_APP_CALCULATOR));
         final Background background = mLauncher.getBackground();