Found the answer through asking in the Amazon forums. Basically, I was wrong in the assumption that withAlarmActions only accepts SNS or SQS actions. It can also accept stop or terminate actions in the form of "arn:aws:automate:us-west-2:ec2:stop". The final line of code edited to be fixed would look like:
.withAlarmActions("arn:aws:sns:us-west-2:xxxxxxxxx:NotifyMe", "arn:aws:automate:us-west-2:ec2:stop");
Here is the full answer if anyone who is curious. https://forums.aws.amazon.com/thread.jspa?messageID=466061񱲍