Install dbus configuration file to /usr/share not /etc

[Fantu]

This was done in Debian packages in version 1.4.1-1

From https://dbus.freedesktop.org/doc/dbus-daemon.1.html:

The standard system bus normally reads additional XML files from /usr/share/dbus-1/system.d. Third-party packages should install the default policies necessary for correct operation into that directory, which has been supported since dbus 1.10 (released in 2015).
The standard system bus normally also reads XML files from /etc/dbus-1/system.d, which should be used by system administrators if they wish to override default policies.
Third-party packages would historically install XML files into /etc/dbus-1/system.d, but this practice is now considered to be deprecated: that directory should be treated as reserved for the system administrator.

[aryoda]

Thanks a lot for your PR (and giving us the context for the dbus config location change) 😄

Please give me a few days to find and perform a test case to avoid a possible regression.

[aryoda]

I am just wondering if we still need to care about uninstalling from /etc too to avoid orphaned files in /etc if the "old" make install was used. This could lead to strange side effects if the same file exists in different versions in /etc and /share.