/usr/share/kservicetypes5/pmc_datasource.desktop is in plasma-mediacenter 5.7.3-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | [Desktop Entry]
Type=ServiceType
X-KDE-ServiceType=Plasma/MediaCenter/DataSource
|