Fix Bazel incompatible changes

I'd like to be able to build rules_scala with `--all_incompatible_changes`

e.g. `cd rules_scala && bazel test //scala:all //test:all --all_incompatible_changes`

It may not be possible to fix every issue now due to transitive dependencies, but we should try to fix the issues from this repository.

Run `cd rules_scala && bazel test //scala:all //test:all --all_incompatible_changes` to reproduce the failures. Trace the reported incompatible-change errors to determine which are owned by this repository versus transitive dependencies, then verify that the repository-owned issues are fixed while rerunning the same targets.

Written by the indexing model from the issue text.