Remote bazel drops `user.bazelrc`s

[keith]

Describe the bug

When using remote bazel, if your repo has the common pattern of putting something like:

try-import %workspace%/user.bazelrc

At the bottom of the .bazelrc, that file isn't uploaded (since it's likely gitignored), and therefore options from it don't apply.

To Reproduce

1. Clone this repo
2. echo "build --invalid_flag" >> user.bazelrc
3. bb build cli <- fails with ERROR: --invalid_flag :: Unrecognized option: --invalid_flag
4. bb remote build cli <- doesn't fail