Baseline: dc724e4e

Important changes:

  - Added a new `max_compatibility_level` attribute to the
    `bazel_dep` directive, which allows version selection to upgrade
    a dependency up to the specified compatibility level.
  - `--experimental_remote_grpc_log` has been renamed to
    `--remote_grpc_log`
  - `--incompatible_remote_build_event_upload_respect_no_cache` is
    now a no-op.

This release contains contributions from many people at Google, as well as Benjamin Peterson, Brentley Jones, Fabian Meumertzheim, George Gensure, Kai Zhang, Oscar Garzon.