Thanks for reporting this. If your own code is not reading this resource file at any point, and only the Urban Airship library is, then it makes sense that Faux Pas would be flagging this file. This particular filename is such a common case, though, that I think it'd be prudent to whitelist it. So this particular case will be fixed for the next release.
You are correct, only Urban Airship library is referencing this (their library also triggers compiler flag errors, might be something worth looking into). Our own code usually only refers to [UAirship defaultConfig] method, which loads the plist. Could maybe fix this error, if one would use the config with name method, which absolutely specifies plist filename.