/usr/share/applications/update-accounts.desktop is in unity-control-center-signon 0.1.8+16.04.20160201-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | [Desktop Entry]
Name=Account update tool
Exec=/usr/lib/x86_64-linux-gnu/update-accounts
NoDisplay=true
Type=Application
X-Ubuntu-Gettext-Domain=credentials-control-center
|