TenantDomain detection isn't correct

[cornholioso]

Regarding: https://github.com/nickrod518/PowerShell-Scripts/blob/master/MSO/OneDrive.psm1

Some assumptions are made with the following statement which are not always true - eg. user email may be [email protected] however the onmicrosoft domain may be different, say companyxy.onmicrosoft.com and the SPO domain is based on this
[string] $TenantDomain = (ConvertTo-Domain $UserPrincipalName)

The following would get the correct name:

    $domains = get-msoldomain                           ## get a list of all domains in tenant
    foreach ($domain in $domains) {                     ## loop through all these domains
        if ($domain.name.contains('onmicrosoft')) {     ## find the onmicrosoft.com domain
            $onname = $domain.name.split(".")           ## split the onmicrosoft.com domain when found at the period. Will produce an array that contains each string as an element
            $tenantname = $onname[0]                    ## the first string in this array is the name of the tenant
        }                                               ## end of find the on.microsoft.com domain
    }