Add workfow for the Anbox Cloud Appliance

[morphis]

This installs everything necessary for the Anbox Cloud Appliance. In essence this consists of a couple of snap packages to install but we also have to switch to the generic kernel as the default kvm one doesn't ship with the binder and ashmem kernel modules we require.

[morphis]

Thanks Simon! Some comments inline.

For reference, you can try this with:

$ snap stop multipass
$ sudo tee /etc/systemd/system/snap.multipass.multipassd.service.d/override.conf <<EOF
[Service]         
Environment="MULTIPASS_WORKFLOWS_URL=https://github.com/morphis/multipass-workflows/archive/refs/heads/add-anbox-cloud-appliance.zip"
EOF
$ sudo systemctl daemon-reload
$ snap start multipass
$ multipass launch anbox-cloud-appliance

Thanks! Ran that locally and worked as expected.

[morphis]

Thanks @Saviq ! Added the suggestion.

[morphis]

Just tested and verified, the update cloud-init configuration works fine