message: Moving the TF monitoring collection API to tf/core:lib.
diff: @@ -668,8 +668,11 @@ cc_library(
  "lib/io/table_builder.h",
  "lib/io/table_options.h",
  "lib/math/math_util.h",
  + "lib/monitoring/collected_metrics.h",
  + "lib/monitoring/collection_registry.h",
  "lib/monitoring/counter.h",
  "lib/monitoring/gauge.h",
  + "lib/monitoring/metric_def.h",
  "lib/monitoring/sampler.h",
  "lib/random/distribution_sampler.h",
  "lib/random/philox_random.h",
  @@ -2016,9 +2019,6 @@ LIB_INTERNAL_PUBLIC_HEADERS = tf_additional_lib_hdrs() + [
  "lib/io/zlib_compression_options.h",
  "lib/io/zlib_inputstream.h",
  "lib/io/zlib_outputbuffer.h",
  - "lib/monitoring/collected_metrics.h",
  - "lib/monitoring/collection_registry.h",
  - "lib/monitoring/metric_def.h",
  "lib/monitoring/mobile_counter.h",
  "lib/monitoring/mobile_gauge.h",
  "lib/monitoring/mobile_sampler.h",
  