Fix crash when no Bluetooth feature in Settings

- Move PreferenceGroup init method out of isAvailable() condition,
  then PreferenceGroup will not be null.
- Update getAvailabilityStatus(), since the controller now may have usb
  and dock.

Bug: 110712414
Test: make -j42 RunSettingsRoboTests
Change-Id: I4d85a42c26fb20d319e7321177b271933be3fdb0

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

@@ -52,7 +52,8 @@ public class PreviouslyConnectedDevicePreferenceController extends BasePreferenc
 
     @Override
     public int getAvailabilityStatus() {
-        return mContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)
+        return (mContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)
+                || mSavedDockUpdater != null)
                 ? AVAILABLE
                 : CONDITIONALLY_UNAVAILABLE;
     }