Previously there were 2 ways to validate the access_token
1. define auth_url, which will send the access_token to
keycloak for validation
2. define absolute user_info_endpoint_url to validate the
custom url
In this patch we have removed the 1st option to validate
everytime with keycloak instead we are taking keyclaok certs
and constructing public key with it and then validating using
access_token using public key and iss(optional).
We are keeping the public key in cache to not to request
keycloak repeatedly.
Change-Id: Ie0551c2f9f8a37debd50e7aebcf35f7143db44f9
kushalagrawal
47fd843000