sysmo-isim-sja2 may come in different configurations, so some may
intentionally lack ADF.USIM or ADF.ISIM. Since select_adf_by_aid() may
raise an exception when selecting a non existent file we should make
sure that the ADF we intend to select is indeed present. A reliable way
to do this is to check if the application is registered in EF.DIR.
Change-Id: Icf6f6b36f246398af408ec432d493fe3f22963dd