Create Custodians
POST https://graph.microsoft.com/v1.0/security/cases/ediscoveryCases/{{ediscoveryCaseId}}/custodians
Request Body
{"email"=>"{{custodianEmail}}"}
POST https://graph.microsoft.com/v1.0/security/cases/ediscoveryCases/{{ediscoveryCaseId}}/custodians
{"email"=>"{{custodianEmail}}"}