Fix commit search on some elasticsearch indexes
What does this MR do?
Ensures that commit search works, even on elasticsearch indexes where the project
rid is created as a string, rather than integer, field
Are there points in the code the reviewer needs to double check?
Why was this MR needed?
Commit search is broken on some indexes at the moment
Screenshots (if relevant)
Does this MR meet the acceptance criteria?
- Changelog entry added, if necessary
- All builds are passing
- Conform by the merge request performance guides
- Conform by the style guides
Branch has no merge conflicts with
master(if it does - rebase it please)
- Squashed related commits together
What are the relevant issue numbers?
Closes #2280 (closed)