title: Android BLE API : multiple Notification
body: <p>According to google BLE Sample code , I design a android application , it's need to connect another BLE Device (TI CC2640 device), the protocol has two UUID ,
  so in SampleGattAttributes.java , I add like this :</p>
  
  <pre><code>public static String UBI_ONGOING_INFO_SERVICE_UUID = "3d963d11-d107-4d7d-918f-61ca2aa836af";
  
  public static String UBI_SYSTEM_INFO_SERVICE_UUID = "3d963d13-d107-4d7d-918f-61ca2aa836af";
  </code></pre>
  
  <p>now I need to read/write Characteristic
  in BluetoothLeService.java:</p>
  
  <pre><code>public final static String EXTRA_DATA_ONGOING =
          "com.example.bluetooth.le.EXTRA_DATA_ONGOING";
  
  public final static String EXTRA_DATA_SYSTEM_INFO =
          "com.example.bluetooth.le.EXTRA_DATA_SYSTEM_INFO";
  
  public final static UUID UUID_UBI_ONGOING_INFO_SERVICE_UUID =
          UUID.fromString(SampleGattAttributes.UBI_ONGOING_INFO_SERVICE_UUID);
  
  public final static UUID UUID_UBI_SYSTEM_INFO_SERVICE_UUID =
          UUID.fromString(SampleGattAttributes.UBI_SYSTEM_INFO_SERVICE_UUID);
  
  private void broadcastUpdate(final String action,final BluetoothGattCharacteristic characteristic){
  ...
  ...
  if (UUID_UBI_SYSTEM_INFO_SERVICE_UUID.equals(characteristic.getUuid())){
    final byte[] data1 = characteristic.getValue();
    ....
    ....
    intent.putExtra(EXTRA_DATA, stringBuilder.toString());
    intent.putExtra(EXTRA_DATA_SYSTEM_INFO, strBuilder.toString());
  }else{
    ...
    ...
    intent.putExtra(EXTRA_DATA, stringBuilder.toString());
    intent.putExtra(EXTRA_DATA_ONGOING, strBuilder.toString());
  }
  
  
  public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic,boolean enabled) {
      mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
  
      if (UUID_UBI_SERVICE_SERVICE_UUID.equals(characteristic.getUuid())) {
          BluetoothGattDescriptor descriptor = characteristic.getDescriptor(UUID.fromString(00002902-0000-1000-8000-00805f9b34fb));
          descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
          mBluetoothGatt.writeDescriptor(descriptor);
       }
  
  if (UUID_UBI_SYSTEM_INFO_SERVICE_UUID.equals(characteristic.getUuid())){
     BluetoothGattDescriptor descriptor1 = characteristic.getDescriptor(00002902-0000-1000-8000-00805f9b34fb);
       descriptor1.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
       mBluetoothGatt.writeDescriptor(descriptor1);
  }
  </code></pre>
  
  <p>then , I can only receive notifications for the first characteristics. 
  how can I receive notifications from both characteristics and show data 
  in DeviceControlActivity.java ? </p>
  
  <p>I am stuck in here for long time , hope someone can help me , thanks. </p>
  
  <p>In fact , I don't need to revise broadcastUpdate function , cause 
  EXTRA_DATA should be process in DeviceControlActivity.</p>