Update RBE toolchain flags. (#364)
Update RBE toolchain flags. (#364)

Do not submit until all PRs to update @bazel_toolchains WORKSPACE pin
are merged.

https://github.com/bazelbuild/bazel-toolchains/issues/216
https://github.com/bazelbuild/continuous-integration/issues/319
bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration