Update overlay multiplayer fix

[ahmanwoods]

• Update overlay multiplayer fix so the Oauth token is retrieved from locally stored Oculus client offline data, rather than a local instance of the Oculus platform
• Remove login option from tray
• Add notification upon launching common multiplayer titles if Oauth token is unable to be retrieved, as this process is automatic.

[CrossVR]

I'd recommend fixing the indentation issues. The comment appears to use spaces and tabs interchangeably.

Other than that it looks good, very ingenious solution.