Currently get extension info test runs only for v2.1 and
v2 compatible mode. Because this tests get "os-create-backup"
extension info which does not exsist in v2 as separate extension.
This commit make that test to run to get 'os-agents' extension
info and run that for v2 also.
NOTE- Due to namespace link and updated date used in extension
detail info, we need to keep separate sample for v2 and v2.1
Change-Id: I643d278bf1916df6f5755c094a4ce7956551403e
40dc5847e2