ECS Service Discovery not respecting TTL when updating service

### Summary
When updating a service or otherwise scaling out ECS tasks for a service that uses Service Discovery, tasks are being stopped before reaching the TTL of the service discovery record(s).

### Description
When updating a service or otherwise scaling out ECS tasks for a service that uses Service Discovery, tasks are being stopped before reaching the TTL of the service discovery record(s).

To reproduce - create an ECS service from a simple "hello world" type task definition that runs forever and does nothing. Set min healthy to 100, max to 200, count to 1. Setup service discovery and create a DNS record with a long TTL, say 300s. Update the service to use a new revision of the task definition (no changes to the task def needed), and note that the tasks are stopped before the TTL time is reached.

### Expected Behavior
ECS Agent should remove the route53 record(s), and then wait to stop the tasks after the TTL duration has elapsed.

### Observed Behavior
ECS Agent does not wait any additional time when stopping tasks for services that use service discovery.

### Environment Details

### Supporting Log Snippets