javaldx: Could not find a Java Runtime Environment! Please ensure that a JVM and the package libreoffice-java-common is installed.

[Norbert]

Steps to reproduce:
1. Boot Ubuntu 20.10 daily ISO
2. Launch libreoffice-calc from its desktop file
3. Monitor the output of error-log by `tail -f ~/.xsession-errors`

Expected results:
* error log is empty

Actual results:
* error log contains lines:

```
javaldx: Could not find a Java Runtime Environment!
Please ensure that a JVM and the package libreoffice-java-common
is installed.
If it is already installed then try removing ~/.config/libreoffice/4/user/config/javasettings_Linux_*.xml
Warning: failed to read path from javaldx
```

Note: also happens for Draw, Impress, Math, StartCenter, Writer, xsltfilter.

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: libreoffice-calc 1:6.4.4-0ubuntu1
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu43
Architecture: amd64
CasperMD5CheckMismatches: ./casper/filesystem.squashfs
CasperMD5CheckResult: skip
CasperVersion: 1.452
CurrentDesktop: MATE
Date: Thu Aug 6 10:10:47 2020
LiveMediaBuild: Ubuntu-MATE 20.10 "Groovy Gorilla" - Alpha amd64 (20200806)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: libreoffice
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
http://iso.qa.ubuntu.com/qatracker/reports/bugs/1890569

[Norbert (nrbrtx)]

Still happens on UM Jammy.