[Pair hearing devices] Add "Saved devices" to show bonded but not connected hearing devices

* BaseHearingDevicePreferenceController will also be used in "Hearing devices", so extract to parent class first.

Bug: 237625815
Test: make RunSettingsRoboTests ROBOTEST_FILTER="(SavedHearingDeviceUpdaterTest|BaseBluetoothDevicePreferenceControllerTest|BluetoothDeviceUpdaterTest|AvailableMediaBluetoothDeviceUpdaterTest|ConnectedBluetoothDeviceUpdaterTest|SavedBluetoothDeviceUpdaterTest)"
Change-Id: I8a492866f48e3a664b9ff78bce5a4f082c0dc465

src/com/android/settings/connecteddevice/AvailableMediaDeviceGroupController.java

@@ -131,7 +131,7 @@ public class AvailableMediaDeviceGroupController extends BasePreferenceControlle
     public void init(DashboardFragment fragment) {
         mFragmentManager = fragment.getParentFragmentManager();
         mBluetoothDeviceUpdater = new AvailableMediaBluetoothDeviceUpdater(fragment.getContext(),
-                fragment, AvailableMediaDeviceGroupController.this);
+                AvailableMediaDeviceGroupController.this, fragment.getMetricsCategory());
     }
 
     @VisibleForTesting

src/com/android/settings/connecteddevice/ConnectedDeviceGroupController.java

@@ -184,7 +184,8 @@ public class ConnectedDeviceGroupController extends BasePreferenceController
         final DockUpdater connectedDockUpdater =
                 dockUpdaterFeatureProvider.getConnectedDockUpdater(context, this);
         init(hasBluetoothFeature()
-                        ? new ConnectedBluetoothDeviceUpdater(context, fragment, this)
+                        ? new ConnectedBluetoothDeviceUpdater(context, this,
+                        fragment.getMetricsCategory())
                         : null,
                 hasUsbFeature()
                         ? new ConnectedUsbDeviceUpdater(context, fragment, this)

src/com/android/settings/connecteddevice/PreviouslyConnectedDevicePreferenceController.java

@@ -125,7 +125,8 @@ public class PreviouslyConnectedDevicePreferenceController extends BasePreferenc
 
     public void init(DashboardFragment fragment) {
         mBluetoothDeviceUpdater = new SavedBluetoothDeviceUpdater(fragment.getContext(),
-                fragment, PreviouslyConnectedDevicePreferenceController.this);
+                PreviouslyConnectedDevicePreferenceController.this, /* showConnectedDevice= */
+                false, fragment.getMetricsCategory());
     }
 
     @Override

src/com/android/settings/connecteddevice/SavedDeviceGroupController.java

@@ -117,7 +117,8 @@ public class SavedDeviceGroupController extends BasePreferenceController
 
     public void init(DashboardFragment fragment) {
         mBluetoothDeviceUpdater = new SavedBluetoothDeviceUpdater(fragment.getContext(),
-                fragment, SavedDeviceGroupController.this);
+                SavedDeviceGroupController.this, /* showConnectedDevice= */true,
+                fragment.getMetricsCategory());
     }
 
     @VisibleForTesting