When we added software raid support, we started calling bootloader
installation. As time went on, we ehnanced that code path for non
RAID cases in order to ensure that UEFI nvram was setup
for the instance to boot properly.
Somewhere in this process, we missed a possible failure case where
the iscsi client tgtadm may return failures. Obviously, the correct
path is to not call iscsi teardown if we don't need to.
Since it was always semi-opportunistic teardown, we can't blindly
catch any error, and if we started iSCSI and failed to tear the
connection down, we might want to still fail, so this change
moves the logic over to use a flag on the agent object which
one extension to set the flag and the other to read it and take
action based upon that.
Change-Id: Id3b1ae5e59282f4109f6246d5614d44c93aefa7c
Story: 2007937
Task: 40395
2a56ee03b6