Update snapshot waiter to use default number of tries
Update snapshot waiter to use default number of tries

- Bumps timeout for snapshots from ~8 minutes to ~27 minutes

[#116063417](https://www.pivotaltracker.com/story/show/116063417)

cloudfoundry-incubator/bosh-aws-cpi-release,cloudfoundry-incubator/bosh-aws-cpi-release,cloudfoundry-incubator/bosh-aws-cpi-release