Merge pull request #1925 from aiven/maintenance_updates_auto_apply

Updated maintenance-window & service-power-cycle to include that

docs/platform/concepts/maintenance-window.rst

@@ -22,4 +22,4 @@ In case of **Apache Kafka®** and **OpenSearch®** the service DNS address resol
 Maintenance updates
 ~~~~~~~~~~~~~~~~~~~
 
-Security updates, platform updates that affect reliability or stability of the service nodes, and quarterly patch updates are always mandatory. Other updates are initially optional. Advance notice is given for all updates. After optional updates have been available for six months, they become mandatory and are applied on the next week's maintenance window at the earliest. This means you have at least 7 days advance notice with exception of critical security updates. These critical updates are applied in the maintenance window of the current week.
+Security updates, platform updates that affect reliability or stability of the service nodes, and quarterly patch updates are always mandatory. Other updates are initially optional. Advance notice is given for all updates. After optional updates have been available for six months, they become mandatory and are applied on the next week's maintenance window at the earliest. This means you have at least 7 days advance notice with exception of critical security updates. These critical updates are applied in the maintenance window of the current week. During service upgrades, maintenance updates are automatically applied and do not require any action from you. 

docs/platform/concepts/service-power-cycle.rst

@@ -52,3 +52,5 @@ When a service is powered on, the following things will happen:
 
     Depending on the service plan, backups have different retention periods. Data will be lost after the retention period.
 
+.. Note:: 
+    Maintenance updates are automatically applied when a service is powered on as new virtual machines are created for the service to run on.