(DOCSP-10561): Kubernetes Operator v1.5.3 release notes (#292)

* (DOCSP-10561): Kubernetes Operator v1.5.3 release notes

* Copy/tech review

Author: melissamahoney-mongodb

source/release-notes.txt

@@ -20,6 +20,30 @@ Release Notes for |k8s-op-full|
       Production Notes </reference/production-notes>
       Known Issues </reference/known-issues>
 
+.. _ent-op-1.5.3:
+
+|k8s-op-full| 1.5.3
+-------------------
+
+*Released 2020-05-29*
+
+Kubernetes Operator Changes
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Passes |onprem| and MongoDB deployment configuration properties as
+:k8sdocs:`Secret environment variables
+</concepts/configuration/secret/#using-secrets-as-environment-variables>`.
+
+Bug Fixes
+~~~~~~~~~
+
+- Correctly configures shutdown timeouts for |onprem| and the Backup    
+  Daemon.
+- Fixes an issue where |k8s-op-short|-watched Secrets and ConfigMaps 
+  triggered unnecessary reconciliations.
+- Fixes an issue where the status of custom resources failed to update
+  in OpenShift 3.11. 
+
 .. _ent-op-1.5.2:
 
 |k8s-op-full| 1.5.2