Proposal: Add Read Only Access to UDev To This Flatpak's Default Permissions

Hello,

If one uses Microsoft Edge on the Steam Deck right now and wishes to setup Xbox Game Pass on this gaming device, they will be lead to this instruction page on Microsoft's website:

https://support.microsoft.com/en-us/topic/xbox-cloud-gaming-in-microsoft-edge-with-steam-deck-43dd011b-0ce8-4810-8302-965be6d53296

Step 8 and 9 of the process requires the user to open a terminal window to enter a command to give Microsoft Edge access to UDev to receive controller input.


I understand the author of this Flatpak has described this as a workaround on the README.md for this repository, but as far as workarounds go, this one seems innocent enough to include it by default.

Having this available out of the box would reduce the steps in this process for new users.

For the Steam Deck particularly this would be a very nice UX improvement, as the Steam Deck's target demographic is not experienced Linux users, in many cases it includes people who have come straight from console gaming. Even if it's just 2 steps, helping those users avoid having to open a terminal to run a command would be nice.

As far as I can tell, this would only require only a one line change to `com.microsoft.Edge.yaml`, inserted after line 35:
```
- --filesystem=/run/udev:ro
```

If the maintainer of this Flatpak agrees I would be happy to make a push request myself to do the file modification.