This warning appears with outdated versions of the Android iBeacon Library, 0.7 or prior. The latest version is 0.7.6 and will not have this warning. The easy solution is to simply upgrade to the latest version of the library available here.
The warning has to do with the way that iBeacon data are passed between the library's background service and your app. Early versions of the library used an "implicit intent" to pass this information, which could theoretically cause iBeacon data to the wrong app if two apps were on the phone using the library simultaneously. For development purposes, it doesn't really matter, but you should use the latest library version if using it in a production app.