/usr/share/dbus-1/interfaces/ is in modemmanager-dev 1.6.8-2ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Bearer.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Call.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.Firmware.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.Location.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.Messaging.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.Modem3gpp.Ussd.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.Modem3gpp.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.ModemCdma.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.Oma.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.Signal.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.Simple.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.Time.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.Voice.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Modem.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Sim.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.Sms.xml
/usr/share/dbus-1/interfaces/org.freedesktop.ModemManager1.xml