Fix member_role_policy_template for Openbao

Why this MR ?

• To close this issue
• We have a bug in the ACL policy template for member_role_policy
• It does not handle the case where the member_role_id: claim is nil in the OIDC JWT token

What does this MR do ?

• Update the ACL policy template for member_role_policy to handle the case where member_role_id: is NOT present in the JWT
• The solution is to as suggested in the docs, to add a guard clause using the index function.
• If member_role_id: claim is NOT present in the JWT, we exclude member_role_policy_template from the list of policy templates

References

• Issue

Screenshots

Logs for project provisioned with buggy template	Logs for project provisioned with fixed template
"policies":["default","project_70/users/direct/user_2","project_70/users/roles/50", "project_70/users/direct/member_role_\u003cno value\u003e"]	"policies":["default","project_75/users/direct/user_2","project_75/users/roles/50"]
"token_policies":["default","project_70/users/direct/user_2","project_70/users/roles/50", "project_70/users/direct/member_role_\u003cno value\u003e"]	"token_policies":["default","project_75/users/direct/user_2","project_75/users/roles/50"]

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