(see <https://docs.fedoraproject.org/en-US/flatpak/>). For one, various paths
need to be configured explicitly, as LO's configure would fall back to hardcoded
/usr paths instead of the /app paths needed here. For another, it is unclear to
me why those three __pycache__ files are not generated, but just not asking to
include them should be harmless.
Forward-ported from f31, combined cherry-pick of:
* bfd5f11376 "Adapt to Flatpak-from-RPM build"
* 385664d08b "Hack libreoffice-multiliblauncher.sh
for flatpak"
* decfe42573 "Fix Flatpak-from-RPM build"
* 093c4953a6 "Fix Flatpak-from-RPM build"
* 3d51346db2 "Fix Flatpak-from-RPM build"
* a9e4c56f32 "Fix flatpak
--with-commons-logging-jar"
a6fe48f5ea
