Add and backfill project_id for p_ci_pipeline_variables
Ref: #463244
What does this MR do and why?
This MR adds and backfills project_id
for p_ci_pipeline_variables
as this is a requirement for Cells1.0.
We have about ~2B records to update which should take ~6 weeks to complete on gitlab.com.
Edited by Max Orefice