Updated bubble bar position to be center aligned with the hotseat

Added a method to the device profile to calculate the vertical center of
the hotseat icons. Simplified the logic for positioning the bubble bar.

Test: TransientBubbleStashControllerTest
Test: PersistentBubbleStashControllerTest
Test: Visual. Go to home page, check that bubble bar is vertically
center aligned with the hotseat
Bug: 345491493
Flag: com.android.wm.shell.enable_bubble_bar

Change-Id: I52f1b94de79f6c912f43a88fcc5c884e20e56310

src/com/android/launcher3/DeviceProfile.java

@@ -2018,6 +2018,18 @@ public class DeviceProfile {
         }
     }
 
+    /**
+     * Returns the number of pixels the hotseat icons vertical center is translated from the bottom
+     * of the screen.
+     */
+    public int getHotseatVerticalCenter() {
+        return hotseatBarSizePx
+                - (isQsbInline ? 0 : hotseatQsbVisualHeight)
+                - hotseatQsbSpace
+                - (hotseatCellHeightPx / 2)
+                + ((hotseatCellHeightPx - iconSizePx) / 2);
+    }
+
     /**
      * Returns the number of pixels the taskbar is translated from the bottom of the screen.
      */