Full abort on validate failure merging orElse.
Previously partial roll back of a branch of an orElse was attempted
if validation failure was observed. Validation here, however, does
not account for what part of the transaction observed inconsistent
state. This commit fixes this by fully aborting and restarting the
(cherry picked from commit 998f2e18ec1a23c987142551f751b3e0f8431970)