Fix KI in test and re-enable for postsubmit.

- The taskbar stashing logic with hardware keyboards was different
  between tests and user experience; aligned the test to be the
  same.
- There is still a previous test failure that only occurred in
  post submit, so also add ScreenRecord to diagnose it
- Once that is resolved, can promote the test to PRESUBMIT.

Test: testQuickSwitchToPreviousAppForTablet
Flag: NA
Fixes: 318544733
Bug: 314873201
Change-Id: Ia813eb0294d759c40d90cec7a8e9a7e0aea2d917

src/com/android/launcher3/util/DisplayController.java

@@ -175,6 +175,13 @@ public class DisplayController implements ComponentCallbacks, SafeCloseable {
         sTransientTaskbarStatusForTests = enable;
     }
 
+    /**
+     * Returns whether the taskbar is pinned in gesture navigation mode.
+     */
+    public static boolean isPinnedTaskbar(Context context) {
+        return INSTANCE.get(context).getInfo().isPinnedTaskbar();
+    }
+
     @Override
     public void close() {
         mDestroyed = true;
@@ -423,6 +430,12 @@ public class DisplayController implements ComponentCallbacks, SafeCloseable {
             }
             return true;
         }
+        /**
+         * Returns whether the taskbar is pinned in gesture navigation mode.
+         */
+        public boolean isPinnedTaskbar() {
+            return navigationMode == NavigationMode.NO_BUTTON && !isTransientTaskbar();
+        }
 
         /**
          * Returns {@code true} if the bounds represent a tablet.