Bug 1238991: Don't connect Bluetooth OPP manager before service channel is known, r=btian

The Bluetooth Opp manager requires the service channel of the remote
service to connect successfully. If the service channel isn't known,
it sends an SDP update request to get the value from the remote device.

The current code will still try to connect with an invalid service
channel. This patch fixes the issue by returning early after sending
the SDP update request.

dom/bluetooth/bluedroid/BluetoothOppManager.cpp

@@ -1640,6 +1640,8 @@ BluetoothOppManager::OnGetServiceChannel(
       OnSocketConnectError(mSocket);
       return;
     }
+
+    return; // We update the service records before we connect.
   }
 
   mSocket->Connect(aDeviceAddress, aServiceUuid,