The previous used QDbusServiceWatcher doesn't work as it does only watch out
for specific services, but the players use different, unpredictable names, so
we need to check all service registrations for mpris players.
BUG: 361367
REVIEW: 127611
media player services are not registered as org.mpris.MediaPlayer2 just
use a service name that starts with that. We need to watch all services
and then filter.
BUG: 352529
Reviewed-by: Albert Vaca
We used to have the following warning: "Connecting to deprecated signal
QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)"
Port away from it as recommended in Qt documentation.
REVIEW: 123637
