Skip role immutable check for Roles Mappings APIs

[cwperks]

Description

@willyborankin I'm opening up a Draft PR that fixes this issue locally, but wanted to get your input too. There are security-dashboards-tests failing because they cannot clean up test data by using the patch API to modify the all_access roles mapping and the request fails with this error:

> curl -XPATCH https://admin:admin@localhost:9200/_plugins/_security/api/rolesmapping/all_access --insecure -H "Content-Type: application/json" --data '
[
        {
        "op": "remove",
        "path": "/users",
        "users": ["jwt_test"]
        }
]
'
{"status":"FORBIDDEN","message":"Resource 'all_access' is static."}

I believe the fix is to skip the validateRoles check on the RolesMapping API. Essentially roles can be static or hidden, but roles mappings cannot be. Any roles mapping is editable.

Test failures seen on this PR: opensearch-project/security-dashboards-plugin#1568
Example integ test run with test failures: https://github.com/opensearch-project/security-dashboards-plugin/actions/runs/6031350472/job/16364885321?pr=1568

This failure is related to the recent change to refactor the REST APIs: #3123

• Category (Enhancement, New feature, Bug fix, Test fix, Refactoring, Maintenance, Documentation)

Bug fix

Check List

• New functionality includes testing
• New functionality has been documented
• Commits are signed per the DCO using --signoff

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[codecov]

Codecov Report

Merging #3272 (8da8e32) into main (0338cdd) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##               main    #3272      +/-   ##
============================================
+ Coverage     63.15%   63.18%   +0.02%     
  Complexity     3448     3448              
============================================
  Files           263      263              
  Lines         20024    20022       -2     
  Branches       3341     3341              
============================================
+ Hits          12647    12650       +3     
+ Misses         5748     5745       -3     
+ Partials       1629     1627       -2     

Files Changed	Coverage Δ
.../security/dlic/rest/api/RolesMappingApiAction.java	96.87% <100.00%> (-0.19%)	⬇️

... and 1 file with indirect coverage changes

[willyborankin]

@cwperks Im on it. Old code checked hidden role only. I will fix it

[cwperks]

Closing this PR. @willyborankin is working on this and will open a PR with a proper fix shortly.