Tried this also →
Enable universe and multiverse repositories
$ sudo add-apt-repository universe
$ sudo add-apt-repository multiverse
$ sudo apt update
$ sudo apt --fix-broken install
$ sudo apt-get install libgconf-2-4 libcanberra-gtk-module
$ sudo apt install ./sdkmanager_2.1.0-11600_amd64.deb
Result:
root@pcbuntu20:/home/pieter-claassens/Downloads# sudo apt-get install libgconf-2-4 libcanberra-gtk-module
Reading package lists… Done
Building dependency tree… Done
Reading state information… Done
Package libcanberra-gtk-module is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
Package libgconf-2-4 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package ‘libgconf-2-4’ has no installation candidate
E: Package ‘libcanberra-gtk-module’ has no installation candidate