message: Update documentation for using benchmark_model_plus_flex
  `--config=monolithic` is required for such builds, particularly when
  building for mobile.
  Fixes issue
diff: @@ -59,6 +59,10 @@ cc_binary(
  ],
  )
  +# As with most target binaries that use flex, this should be built with the
  +# `--config=monolithic` build flag, e.g.,
  +# bazel build --config=monolithic --config=android_arm64 \
  +# -c opt --cxxopt='--std=c++14' :benchmark_model_plus_flex
  tf_cc_binary(
  name = "benchmark_model_plus_flex",
  srcs = [
  