Fix swift MaaS check/alarm setup

* Metric names adjusted to be correct
* Thresholds added for checks where required
* Moved swift checks into swift_maas so swift checks aren't installed for non-swift deploys
* Fixed targeted host groups for swift checks

Change-Id: I88cddb4461d2f0814108d0bec1f739452adc536b
Closes-Bug: #1401696
(cherry picked from commit b75ac5bb13fc669347d7f98159ed047d294e2b1f)