Allow SnapshotBackedReadTransaction customization
In some specific cases we need to customize abort-like handling,
which is already implemented for write-like transactions, but is
not present for read-only transaction.
This patch adds the capability to attach a close() handler and
makes sure AbstractSnapshotBackedTransactionChain takes advantage
of it.
JIRA: CONTROLLER-1879
Change-Id: Ic7027956556b5dd25120ee81613a6151e5dbc501
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
(cherry picked from commit
bd73bf5803137b27e25a647ff056da3f59e0a682)