Don't send a value changed notification when a characteristic is written

device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm

Index: device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm
diff --git a/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm b/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm
index db28fb9df011cd396d3b02e91cee3369fc45dede..55dff120c6eb616c888ff472ec0e7270cd16c45e 100644
--- a/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm
+++ b/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.mm
@@ -316,9 +316,6 @@ void BluetoothRemoteGattCharacteristicMac::DidWriteValue(NSError* error) {
     callbacks.second.Run(error_code);
     return;
   }
-  NSData* nsdata_value = cb_characteristic_.get().value;
-  const uint8_t* buffer = static_cast<const uint8_t*>(nsdata_value.bytes);
-  std::vector<uint8_t> gatt_value(buffer, buffer + nsdata_value.length);
   gatt_service_->GetMacAdapter()->NotifyGattCharacteristicValueChanged(this,
                                                                        value_);
   callbacks.first.Run();