Review of Autoscaling policy for Open Search MIG

[mbdebian]

The current autoscaling policy needs to be reviewed from its current configuration:

• Initialisation period: 60 seconds
• CPU utilisation: 35%

As it can be seen here

To more sensible values:

• Initialisation period: 20 seconds (probably enough for Elastic Search to get the cluster ready, please verify)
• CPU utilisation: 65%