Merge branch 'sh-migrate-can-push-to-deploy-keys-projects-10-2' into 'security-10-2'

[10.2] Migrate `can_push` column from `keys` to `deploy_keys_project`

See merge request gitlab/gitlabhq!2275

(cherry picked from commit b07115bbf3a6f2340e88213f51f699302e6af1d9)

5382c682 Backport to 10.2