enabling xrdp on Multipass unable to connect

**Describe the bug**
followed this guide https://multipass.run/docs/set-up-a-graphical-interface#heading--using-x11-forwarding
on Mac apple silicon when connecting from Mac via MS Remote Desktop app or screensharing app on Mac both fail. Logs on ubuntu show this

Mar 03 22:03:09 proven-troll xrdp[29696]: [ERROR] Cannot read private key file /etc/xrdp/key.pem: Permission denied
Mar 03 22:03:09 proven-troll xrdp[29696]: [ERROR] libxrdp_force_read: header read error
Mar 03 22:03:09 proven-troll xrdp[29696]: [ERROR] [ITU-T X.224] Connection Sequence: CR-TPDU (Connection Request) failed
Mar 03 22:03:09 proven-troll xrdp[29696]: [ERROR] xrdp_sec_incoming: xrdp_iso_incoming failed
Mar 03 22:03:09 proven-troll xrdp[29696]: [ERROR] xrdp_rdp_incoming: xrdp_sec_incoming failed
Mar 03 22:03:09 proven-troll xrdp[29696]: [ERROR] xrdp_process_main_loop: libxrdp_process_incoming failed
Mar 03 22:03:09 proven-troll xrdp[29696]: [ERROR] xrdp_iso_send: trans_write_copy_s failed
Mar 03 22:03:09 proven-troll xrdp[29696]: [ERROR] Sending [ITU T.125] DisconnectProviderUltimatum failed

looked through guide see no mention of configuring anything else, have I missed something

**To Reproduce**
How, and what happened?
1. follow this guide https://multipass.run/docs/set-up-a-graphical-interface#heading--using-x11-forwarding on apple silicon Mac
1. try to connect via rdp on same device

**Expected behavior**
connect to rep

**Logs**
Please provide logs from the daemon, see [accessing logs](https://multipass.run/docs/accessing-logs) on where to find them on your platform.

**Additional info**
- OS: Mac OS 14.1.1
- `multipass version` multipass 1.13.1+mac
multipassd 1.13.1+mac
- `multipass info --all`
- Name: proven-troll
State: Running
Snapshots: 0
IPv4: 192.168.64.5
Release: Ubuntu 22.04.4 LTS
Image hash: f19e2cf2d2e5 (Ubuntu 22.04 LTS)
CPU(s): 2
Load: 0.05 0.04 0.01
Disk usage: 4.6GiB out of 19.3GiB
Memory usage: 251.2MiB out of 7.7GiB
- `multipass get local.driver`
emu
**Additional context**
Add any other context about the problem here.

Start with the graphical-interface guide's X11-forwarding section and reproduce the connection attempt on macOS 14.1.1 with Multipass 1.13.1 and Ubuntu 22.04. Check the xrdp log at /etc/xrdp/key.pem, then verify that the documented setup permits an RDP connection or identify the missing configuration needed for it.

Written by the indexing model from the issue text.