Modify the members of a contact group owned by the authenticated user. The only system contact
groups that can have members added are `contactGroups/myContacts` and `contactGroups/starred`.
Other system contact groups are deprecated and can only have contacts removed.
Create a request for the method "members.modify".
This request holds the parameters needed by the people server. After setting any optional
parameters, call the
AbstractGoogleClientRequest.execute() method to invoke the remote operation.