The --preserve-merges (-p) option was replaced by --rebase-merges (-r).
This fixes the following error when using git version 2.34.0:
Errors running git rebase -p -i remotes/gerrit/stable/xena
fatal: --preserve-merges was replaced by --rebase-merges
In order to keep compatibility with git < 2.18.0 we detect the git
version and use the old --preserve-merges flag when the version is older
than 2.18.0.
Co-Authored-By: Clark Boylan <clark.boylan@gmail.com>
Change-Id: I04de3d0f20aa6bafcf746b7706d61dd9b9af296c
7182166ec0