Update placement of the nav bar in persistent taskbar for 3 button nav

Implemented nav bar placement update to be located opposite to the
bubble bar.
When bubble bar is moved to the other side of the bar, 3 button nav will
swap sides (without animation).
If taskbar has to be repositioned it does that with the animation.

Test: TaskbarViewControllerTest
Bug: 346381754
Flag: com.android.wm.shell.enable_bubble_bar
Change-Id: Id031706183c60cbd9c67537b01530acb43bae614

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

@@ -28,6 +28,7 @@ import androidx.annotation.Nullable;
 import com.android.internal.jank.Cuj;
 import com.android.launcher3.taskbar.bubbles.BubbleBarViewController;
 import com.android.systemui.shared.system.InteractionJankMonitorWrapper;
+import com.android.wm.shell.Flags;
 import com.android.wm.shell.shared.bubbles.BubbleBarLocation;
 
 /**
@@ -127,4 +128,10 @@ public class TaskbarViewCallbacks {
         }
         return null;
     }
+
+    /** Returns true if bubble bar controllers present and enabled in persistent taskbar. */
+    public boolean isBubbleBarEnabledInPersistentTaskbar() {
+        return Flags.enableBubbleBarInPersistentTaskBar()
+                && mControllers.bubbleControllers.isPresent();
+    }
 }