ghuang

Version: 2.20 Pretty sure this bug is caused by not null checking this line: https://github.com/airbnb/billow/blob/master/src/main/java/com/airbnb/billow/ElasticsearchCluster.java#L49 `getDedicatedMasterCount()` returns `Integer` object and could be null, so we need to do a null...

### Describe the bug We are using [InstanceTerminatedWaiter](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/ec2#InstanceTerminatedWaiter) to wait for a few ASG-managed instances to be in "terminated" state after we delete the ASG. However, we discovered that this...