If we try to create snapshot from share that is not snapshottable
we expect error that it is not possible and proper description for it.
Now we get some abstract message
"ERROR: Unable to process the contained instructions".
So, make API provide proper information about error.
Change-Id: I16a2f7c80102159c30f91af7e045e73ee3df7f89
Closes-Bug: #1496408