Bazel CI: Assign a unique label to the RBE job in order to avoid confusion.
Bazel CI: Assign a unique label to the RBE job in order to avoid confusion.

Previously it was just named "18.04 LTS (OpenJDK 11, gcc 7.4.0)", which happens to be the label of the local 18.04 job, too.

PiperOrigin-RevId: 424613712

cushon/bazel,katre/bazel,cushon/bazel,katre/bazel,cushon/bazel,katre/bazel,ButterflyNetwork/bazel,cushon/bazel,bazelbuild/bazel,ButterflyNetwork/bazel,katre/bazel,bazelbuild/bazel,bazelbuild/bazel,katre/bazel,bazelbuild/bazel,bazelbuild/bazel,cushon/bazel,ButterflyNetwork/bazel,ButterflyNetwork/bazel,ButterflyNetwork/bazel,bazelbuild/bazel,cushon/bazel,ButterflyNetwork/bazel,katre/bazel