Return "sub" claim as subject identifier, not "email".

[gspadotto]

Description:
The "getAuthenticateUser" method shoud return the value of "sub" claim rather than the
"email" claim that might change over time.

So this:

@Override
    protected String getAuthenticateUser(AuthenticationContext context, Map<String, Object> jsonObject, OAuthClientResponse token) {
        if (jsonObject.get(OIDCAuthenticatorConstants.Claim.EMAIL) == null) {
            return (String) jsonObject.get("sub");
        } else {
            return (String) jsonObject.get(OIDCAuthenticatorConstants.Claim.EMAIL);
        }
    }

should become this:

@Override
    protected String getAuthenticateUser(AuthenticationContext context, Map<String, Object> jsonObject, OAuthClientResponse token) {
            return (String) jsonObject.get("sub");
    }

Suggested Labels:
wso2,federated,google,oidc,outbound

Suggested Assignees:

Affected Product Version:
WSO2 Identity Server 5.*

OS, DB, other environment details and versions:

Steps to reproduce:

Related Issues:
Related to issue #16