fix(kc-saml-plugin): create IDP request error for individual metedata elements

[pujavs]

Describe the bug
Error while creating IDP with individual elements

To Reproduce
Steps to reproduce the behavior:

1. Invoke POST IDP method for individual elements
2. Error reported but IDP created in DB and not in KC server

Expected behavior
IDP should be created without error on KC server and Jans DB

Screenshots

Request payload:
{
"name": "test02",
"singleSignOnServiceUrl": "https://",
"idpEntityId": "https://",
"displayName": "new test",
"description": "desc",
"realm": "master",
"nameIDPolicyFormat": "urn:mace:shibboleth:1.0:nameIdentifier"
}

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.

[pujavs]

@duttarnab & @jv18creator -> Fixed this issue via PR 7238