Feature Request: expose absolute_session_timeout and idle_sesison_timeout options

Description

In order to meet their compliance needs, customer has a need for authservice to end active sessions after 12 hours and idle sessions after 15 minutes. The upstream chart for authservice supports these options with two variables, absolute_session_timeout and idle_session_timeout, respectively. Customer would like for these variables to be exposed in this chart and in BB at the top level so they can configure authservice out of the box to meet their needs without having to define custom chains for every service.

Options need to added to https://repo1.dso.mil/platform-one/big-bang/apps/core/authservice/-/blob/main/chart/templates/secret.yaml , should allow for both overriding at the global level and per-chain.