Fix KeyError exception when scheduling to child cell.

Fix typo 'security_group' and update related unit tests.

Fix bug #1193233

Change-Id: I6d92759b0d7e2ce81c2065a4eada35c559ccbcd7
Merge "Fix KeyError exception when scheduling to child cell."
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp