[rhos-release] Retry getting the rhos-release rpm
[rhos-release] Retry getting the rhos-release rpm

Currently the retry only happens if a specific message returns
in the result. In this patch we make it retry until it succeeds
and also change the delay to 10 seconds.

This will hopefully improve the resilience of this task.

Change-Id: I8c9ad59eab65c0a04860180269b2eb6a6eac08ee

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared