Add Quick Settings shortcut option into Hearing Devices accessibility settings page

* In Android V, we can add qs as one of the accessibility shortcut option to be more discoverable.

Bug: 338327560
Flag: EXEMPT bugfix
Test: check shortcut option in hearing devices settings page
Change-Id: I60d4da2432605a5369eb87c1e594539d40c53ae8

src/com/android/settings/accessibility/AccessibilityHearingAidsFragment.java

@@ -97,13 +97,12 @@ public class AccessibilityHearingAidsFragment extends AccessibilityShortcutPrefe
 
     @Override
     protected ComponentName getTileComponentName() {
-        // Don't have quick settings tile for now.
-        return null;
+        return AccessibilityShortcutController.ACCESSIBILITY_HEARING_AIDS_TILE_COMPONENT_NAME;
     }
 
     @Override
     protected CharSequence getTileTooltipContent(int type) {
-        // Don't have quick settings tile for now.
+        // No tooltip to be shown
         return null;
     }