Add bluetooth discoverable footer preference in connected devices page

* For fix the TreeHugger error in pi-dev, cherry pick the ag/4042014 in
  master and fix TreeHugger error. Change android.support.v7.* to androidx.*
* Dynamicly add preference in controller
* Add test cases for DiscoverableFooterPreferenceController

Bug: 79294219
Test: make -j50 RunSettingsRoboTests
Change-Id: Id4c1e86c9a0a0cd69d8106a18f2cf4a0fa31782b

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

@@ -26,8 +26,10 @@ import com.android.settings.dashboard.DashboardFragment;
 import com.android.settings.dashboard.SummaryLoader;
 import com.android.settings.nfc.NfcPreferenceController;
 import com.android.settings.search.BaseSearchIndexProvider;
+import com.android.settingslib.core.AbstractPreferenceController;
 import com.android.settingslib.search.SearchIndexable;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
@@ -61,12 +63,27 @@ public class ConnectedDeviceDashboardFragment extends DashboardFragment {
         return R.xml.connected_devices;
     }
 
+    @Override
+    protected List<AbstractPreferenceController> createPreferenceControllers(Context context) {
+        return buildPreferenceControllers(context);
+    }
+
+    private static List<AbstractPreferenceController> buildPreferenceControllers(Context context) {
+        final List<AbstractPreferenceController> controllers = new ArrayList<>();
+        final DiscoverableFooterPreferenceController discoverableFooterPreferenceController =
+                new DiscoverableFooterPreferenceController(context);
+        controllers.add(discoverableFooterPreferenceController);
+
+        return controllers;
+    }
+
     @Override
     public void onAttach(Context context) {
         super.onAttach(context);
         use(AvailableMediaDeviceGroupController.class).init(this);
         use(ConnectedDeviceGroupController.class).init(this);
         use(PreviouslyConnectedDevicePreferenceController.class).init(this);
+        use(DiscoverableFooterPreferenceController.class).init(this);
     }
 
     @VisibleForTesting