don't add Android application record (AAR) in the NDEF push message

This allows the system to show a chooser dialog if multiple applications can handle "bitcoin:" uris.

**Note for other readers:** This only takes effect when doing a NDEF push (aka "Android Beam") at the main screen of the Bitcoin Wallet. If you perform a Android beam in the "request payment" screen the wallet will send a Payment Request (and thus the receiving application also needs to support payment requests).

![chooser_dialog_send_bitcoins](https://cloud.githubusercontent.com/assets/285900/2955280/519106ba-da7e-11e3-9b27-8791b9566348.png)