Remove unnecessary notify in BT preference

notifyHierarchyChanged() is used before when we have
connected/disconnect deivce in same list. So only use it in
DevicePickerFragment.java, not other normal fragments.

Also that call will rebuild whole preference list, which is heavy.

Bug: 119479725
Test: Manual
Change-Id: I06cf221588001b38634fec9f02dee8bc1e561ea8

src/com/android/settings/bluetooth/DevicePickerFragment.java

@@ -151,6 +151,12 @@ public final class DevicePickerFragment extends DeviceListPreferenceFragment {
         }
     }
 
+    @Override
+    protected void initDevicePreference(BluetoothDevicePreference preference) {
+        super.initDevicePreference(preference);
+        preference.setNeedNotifyHierarchyChanged(true);
+    }
+
     @Override
     public void onBluetoothStateChanged(int bluetoothState) {
         super.onBluetoothStateChanged(bluetoothState);