I'm developing an application which can be installed and opened via an AndroidApplicationRecord (AAR, see http://developer.android.com/guide/topics/nfc/nfc.html).
If a user installs the app coming from other sources I'm adding a Google Analytics referrer to the Google Play link in order to track the source of installation.
Is there a way to add this referrer to the AAR or as an additional NDEFRecord so that this source can be tracked as well?
The process behind the AAR is completely automatic. The AAR contains the package name of the app and nothing else. Android will then search for that package name in the Play Store app. So no way to add anything to that, as far as I can tell.
What you could try instead of sharing an AAR, is sharing an URI record containing a Play store URI with your Google Analytics referrer in it. I don't know much about Google Analytics, but it looks to me like you can catch the referrer upon installation of your app, see e.g Get Android Google Analytics referrer tag and Get referrer after installing app from Android Market.
Yet another approach could be to track the sharing events using Google Analytics in the already installed app when it shares the AAR to another device.