oidc-auth-apps fails to apply in kubernetes version 1.21.3

[Jerry Sun]

Brief Description
-----------------
oidc-auth-apps fails to apply with dex pod logs showing the following: failed to inspect service account token: jwt claim "kubernetes.io/serviceaccount/namespace" not found
This appears to be related to the kubernetes upversioning to 1.21.3, as described here: https://github.com/dexidp/dex/issues/2082#issuecomment-818124478

Severity
--------
Major: System/Feature is usable but degraded

Steps to Reproduce
------------------
Deploy oidc-auth-apps on a load from today

Expected Behavior
------------------
oidc-auth-apps applies successfully

Actual Behavior
----------------
oidc-auth-apps fails to apply

Reproducibility
---------------
100% reproducible

System Configuration
--------------------
multi-node system

Branch/Pull Time/Commit
-----------------------
2021-10-27

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/oidc-auth-armada-app/+/815756

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/oidc-auth-armada-app/+/815756
Committed: https://opendev.org/starlingx/oidc-auth-armada-app/commit/2576b55249735d30ba7f34a46ab9544e37f91228
Submitter: "Zuul (22348)"
Branch: master

commit 2576b55249735d30ba7f34a46ab9544e37f91228
Author: Jerry Sun <email address hidden>
Date: Wed Oct 27 17:33:47 2021 -0400

    Dex pods fail on kubernetes version 1.21.3

    Dex pod is crashing due to a recent kubernetes upversioning to 1.21.3.
    This causes oidc-auth-apps to fail to apply. This commit implements
    the fix suggested for it upstream:
    https://github.com/dexidp/dex/issues/2082#issuecomment-818124478

    Test Plan:
    PASS: apply oidc-auth-apps on kubernetes version 1.18.1
    PASS: apply oidc-auth-apps on kubernetes version 1.19.13
    PASS: apply oidc-auth-apps on kubernetes version 1.20.9
    PASS: apply oidc-auth-apps on kubernetes version 1.21.3

    Change-Id: Ide9376820647fb46dfd27ea56623dfeefce9f4dd
    Closes-Bug: 1948981
    Signed-off-by: Jerry Sun <email address hidden>