When running `repo rebase -m` (`--onto-manifest`), the command uses the
raw `revisionExpr` from the manifest (e.g. `main`) directly as the
`--onto` target. This can fail or behave incorrectly if it should
reference the local tracking branch (e.g. `refs/remotes/<remote>/main`).
Resolve `project.revisionExpr` to its local tracking branch using
`project.GetRemote().ToLocal()`. Fall back to using the raw
`revisionExpr` value if the resolution fails (raising a `GitError`).
Bug: 532028666
Change-Id: I4c1bca1374a5842688be227f6aa2afffcdad5397
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/604941
Reviewed-by: Brian Gan <brgan@google.com>
Tested-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Gavin Mak <gavinmak@google.com>
Gavin Mak