fix import of ssh keys in answers bw compat support

examples/answers-lvm.yaml

@@ -52,7 +52,11 @@ Identity:
   # ubuntu
   password: '$6$wdAcoXrU039hKYPd$508Qvbe7ObUnxoj15DRCkzC3qO7edjH0VV7BPNRDYK4QR8ofJaEEF2heacn0QgD.f8pO8SNp83XNdWG6tocBM1'
 SSH:
-  install_server: false
+  install_server: true
+  pwauth: false
+  authorized_keys:
+    - |
+      ssh-rsa AAAAAAAAAAAAAAAAAAAAAAAAA # ssh-import-id lp:subiquity
 SnapList:
   snaps:
     hello:

subiquity/controllers/ssh.py

@@ -101,7 +101,7 @@ class SSHController(BaseController):
                 return
             user_spec, ssh_import_id, key_material, fingerprints = result
             if 'ssh-import-id' in self.all_answers.get("Identity", {}):
-                user_spec['ssh_keys'] = key_material.splitlines()
+                user_spec['authorized_keys'] = key_material.splitlines()
                 self.loop.set_alarm_in(0.0,
                                        lambda loop, ud: self.done(user_spec))
             else: