Add new preference class MasterSwitchPreference.

- Add a new preference type that has Title and optional summary on the
  left, and a toggle switch on the right. Clicking the left part of the
  preference will open a settings screen.
- Update Connected devices->Bluetooth to use this new preference.
- Refactor BluetoothSettings and BluetoothEnabler to share code between
  the new bluetooth preference controller and the bluetooth setting.

Bug: 34280769
Test: make RunSettingsRoboTests
Change-Id: I109ecdba640ecdd4748a6e5b2b4f4c47cbf653fd

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

@@ -20,7 +20,10 @@ import android.provider.SearchIndexableResource;
 
 import com.android.internal.logging.nano.MetricsProto;
 import com.android.settings.R;
+import com.android.settings.bluetooth.BluetoothMasterSwitchPreferenceController;
+import com.android.settings.bluetooth.Utils;
 import com.android.settings.core.PreferenceController;
+import com.android.settings.core.lifecycle.Lifecycle;
 import com.android.settings.dashboard.DashboardFragment;
 import com.android.settings.deviceinfo.UsbBackend;
 import com.android.settings.nfc.NfcPreferenceController;
@@ -37,6 +40,7 @@ public class ConnectedDeviceDashboardFragment extends DashboardFragment {
 
     private static final String TAG = "ConnectedDeviceFrag";
     private UsbModePreferenceController mUsbPrefController;
+    private BluetoothMasterSwitchPreferenceController mBluetoothPreferenceController;
 
     @Override
     public int getMetricsCategory() {
@@ -61,13 +65,19 @@ public class ConnectedDeviceDashboardFragment extends DashboardFragment {
     @Override
     protected List<PreferenceController> getPreferenceControllers(Context context) {
         final List<PreferenceController> controllers = new ArrayList<>();
+        final Lifecycle lifecycle = getLifecycle();
         final NfcPreferenceController nfcPreferenceController =
                 new NfcPreferenceController(context);
-        getLifecycle().addObserver(nfcPreferenceController);
+        lifecycle.addObserver(nfcPreferenceController);
         controllers.add(nfcPreferenceController);
         mUsbPrefController = new UsbModePreferenceController(context, new UsbBackend(context));
-        getLifecycle().addObserver(mUsbPrefController);
+        lifecycle.addObserver(mUsbPrefController);
         controllers.add(mUsbPrefController);
+        mBluetoothPreferenceController =
+            new BluetoothMasterSwitchPreferenceController(
+                context, Utils.getLocalBtManager(context));
+        lifecycle.addObserver(mBluetoothPreferenceController);
+        controllers.add(mBluetoothPreferenceController);
         return controllers;
     }