SUMMARY
 A user raised an issue where they can't write files on their system
with the Snap package. We have several activities that allow to write
the output (for example "sketch") on the filesystem (which should be
~/.local/share/GCompris/sketch/test.png).

We use the path:
QStandardPaths::writableLocation(QStandardPaths::GenericDataLocation)
+ QLatin1String("/GCompris")) to set the folder name.

STEPS TO REPRODUCE
1. Open GCompris
2. Open sketch activity (the last section allows to search an activity by name)
3. Draw something, on the right panel, Save the file. The operation is told successful but the user is unable to find the file in the filesystem.

OBSERVED RESULT
No file created

EXPECTED RESULT
File should be accessible under ~/.local/share/GCompris/sketch/

SOFTWARE/OS VERSIONS
Snap version of GCompris

ADDITIONAL INFORMATION