RANGER-5342: USER-role users with names similar to admin or keyadmin …

[dineshkumar-yadav]

…can query those admin/keyadmin users.

What changes were proposed in this pull request?

This change will prevent users with the USER role from fetching details of roles other than USER.

How was this patch tested?

-- build with mvn clean install
-- tested below REST API working as expected

1. curl --insecure -k -v -u 'user:pass' -H 'Accept: application/json, text/plain, /' '{hostname}:{port}/service/xusers/users?pageSize=10000&userRole=ROLE_SYS_ADMIN'
2. curl --insecure -k -u 'user:pass' -H 'Accept: application/json, text/plain, /' '{hostname}:{port}/service/xusers/users?pageSize=10000&userRole=ROLE_KEY_ADMIN'
3. curl --insecure -k -v -u 'user:pass' -H 'Accept: application/json, text/plain, /' '{hostname}:{port}/service/xusers/users?pageSize=10000&userRoleList=ROLE_KEY_ADMIN&userRoleList=ROLE_SYS_ADMIN'