APP-5003 : Fixes maximum token TTE to 5 years

[0xquark]

Description

Set maximum token validity to 5 years in order to avoid issue with keycloack 2038 bug which leads to integer overflow by setting negative value.

Related Issue

APP-5003

Checklist

• My code follows the code style of this project
• I have added tests to cover my changes (if applicable)
• I have updated documentation (if applicable)
• All the checks and tests are passing locally
• I have verified that the changes works as expected

Further Comments

[Aryamanz29]

Looks good!
I would also add a code comment for MaxValidity:

// The value was previously set to 13 years (409968000 secs).
// It has been reverted to 5 years due to an integer overflow issue in Keycloak.
// https://github.com/keycloak/keycloak/issues/19671
MaxValidity  = 157680000  // 5 years in seconds