Allow custom actions in Differential to explicitly override "accept" stickiness
Summary:
See PHI431. Ref T13102. An install is interested in a custom "non-sticky" accept action, roughly.
On the one hand, this is a pretty hacky patch. However, I suspect it inches us closer to T731, and I'm generally comfortable with exploring the realms of "Accept Next Update", "Unblock Without Accepting", etc., as long as most of it doesn't end up enabled by default in the upstream.
Test Plan:
- Accepted and updated revisions normally, saw accepts respect global stickiness.
- Modified the "Accept" action to explicitly be unsticky, saw nonsticky accept behavior after update.
Maniphest Tasks: T13102
Differential Revision: https://secure.phabricator.com/D19211