Added scrim visibility check.

Scrim view was not shown because the TaskbarScrimViewController did not
check taskbar visibility on initialization. Added the check to fix the
issue.

Fixes: 353583417
Flag: com.android.wm.shell.enable_bubble_bar
Test: manual
Switch task bar to transient mode on overview screen or inside an
application. Expand bubble bar.

Change-Id: Ia8a05802a779a4bac70906e7e52ac6650308c85c

quickstep/src/com/android/launcher3/taskbar/TaskbarViewController.java

@@ -229,6 +229,13 @@ public class TaskbarViewController implements TaskbarControllers.LoggableTaskbar
         mActivity.removeOnDeviceProfileChangeListener(mDeviceProfileChangeListener);
     }
 
+    /**
+     * Gets the taskbar {@link View.Visibility visibility}.
+     */
+    public int getTaskbarVisibility() {
+        return mTaskbarView.getVisibility();
+    }
+
     public boolean areIconsVisible() {
         return mTaskbarView.areIconsVisible();
     }