Make indicator-application hack work in flatpak
Flatpak doesn't share $XDG_RUNTIME_DIR with the host making QSystemTrayIcon not to work on Xubuntu/Ubuntu MATE/Ubuntu Budgie.
Although, it shares a subfolder, according to https://docs.flatpak.org/en/latest/sandbox-permissions.html
Amends 0baa2663
Pick-to: 6.3 6.2 5.15 Change-Id: I2d0043fc5a4c2c51e8fa1a920f3cada3b07eba6d Reviewed-by: Dmitry Shachnev mitya57@gmail.com Reviewed-by: Aleix Pol Gonzalez aleixpol@kde.org