fix not supplying snaps in autoinstall, oops

scripts/runtests.sh

@@ -18,7 +18,9 @@ for answers in examples/answers*.yaml; do
         exit 1
     fi
 done
-timeout --foreground 60 sh -c "LANG=C.UTF-8 python3 -m subiquity.cmd.tui --autoinstall examples/autoinstall.yaml --dry-run --machine-config examples/simple.json"
+timeout --foreground 60 sh -c "LANG=C.UTF-8 python3 -m subiquity.cmd.tui --autoinstall examples/autoinstall.yaml \
+                               --dry-run --machine-config examples/simple.json \
+                               --kernel-cmdline 'autoinstall console=$(tty)'"
 python3 scripts/validate-yaml.py .subiquity/subiquity-curtin-install.conf \
         debconf_selections.subiquity='"eek"'
 grep 'finish: subiquity/InstallProgress/postinstall/install_package1: SUCCESS: installing package1' \

subiquity/controllers/snaplist.py

@@ -105,6 +105,7 @@ class SnapdSnapInfoLoader:
 class SnapListController(SubiquityController):
 
     autoinstall_key = "snaps"
+    autoinstall_default = []
     autoinstall_schema = {
         'type': 'array',
         'items': {