/usr/share/dbus-1/interfaces/ is in modemmanager 0.5.2.0-0ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/dbus-1/interfaces/mm-mobile-error.xml
/usr/share/dbus-1/interfaces/mm-modem-connect-error.xml
/usr/share/dbus-1/interfaces/mm-modem-error.xml
/usr/share/dbus-1/interfaces/mm-serial-error.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.Modem.Cdma.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.Modem.Gsm.Card.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.Modem.Gsm.Contacts.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.Modem.Gsm.Hso.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.Modem.Gsm.Network.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.Modem.Gsm.SMS.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.Modem.Gsm.Ussd.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.Modem.Gsm.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.Modem.Location.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.Modem.Simple.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.Modem.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager.xml