There has been a long-standing misconception that git-review pushes
automatically rebased changes by default. It does not, but our
documentation and context help have been less than clear on that
point, contributing to this impression. Try to do a better job of
explaining that the default rebasing performed by git-review is
purely exploratory, and used only to notify users about possible
merge conflicts with their target branch before pushing a change.
Change-Id: I3c841af5ff9430a0de4d9dc9526dd3be6ab53ad2
7009d7d03d