Feature flag: adding of use_core_delta_islands
What does this MR do?
Gitaly starts using a core delta island feature for pack reuse gitaly!1775 (merged).
Introduction of this new flag will allow to switch between running repack with/without usage of core delta islands.
If there would be more good than bad the feature flag would be removed and core delta islands usage would be enable by default.
Part of: gitaly#1519 (closed)
Availability and Testing
No additional testing required.