The `update-java-alternatives` script does not update the symbolic link `/usr/lib/jvm/default-java` generated by the `default-jre-headless` package

[Jacopo De Amicis]

This causes for instance `javaws` not to be able to use jre-8 even after `update-java-alternatives --set java-1.8.0-openjdk-amd64` and requires to manually change the link.

I am not sure it's completely relevant to the `java-common` package (maybe more to `default-jre-headless`), but I report it here because the script belongs to this package.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: java-common 0.68ubuntu1~18.04.1
ProcVersionSignature: Ubuntu 4.15.0-43.46-generic 4.15.18
Uname: Linux 4.15.0-43-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.7
Architecture: amd64
CurrentDesktop: XFCE
Date: Tue Oct 22 18:54:02 2019
Dependencies:

InstallationDate: Installed on 2018-07-06 (473 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
PackageArchitecture: all
SourcePackage: java-common
UpgradeStatus: No upgrade log present (probably fresh install)

[Matthias Klose (doko)]

/usr/lib/jvm/default-java is used for packaging and is not supposed to be handled by alternatives.

javaws shouldn't rely on that.