message: Fix Gauge bucket for tf.data.getNextGen metrics and also fix typo in comment for previous Sampler metrics.
diff: @@ -45,13 +45,13 @@ auto* graph_run_time_usecs_histogram = monitoring::Sampler<0>::New(
  auto* graph_run_input_tensor_bytes = monitoring::Sampler<0>::New(
  {"/tensorflow/core/graph_run_input_tensor_bytes",
  "The size of input tensors in bytes."},
  - // Power of 2 with bucket count 14 (256G)
  - {monitoring::Buckets::Exponential(1, 4, 20)});
  + // Power of 2 with bucket count 14 (256MB)
  + {monitoring::Buckets::Exponential(1, 4, 14)});
  auto* graph_run_output_tensor_bytes = monitoring::Sampler<0>::New(
  {"/tensorflow/core/graph_run_output_tensor_bytes",
  "The size of output tensors in bytes."},
  - // Power of 2 with bucket count 14 (256G)
  + // Power of 2 with bucket count 14 (256MB)
  {monitoring::Buckets::Exponential(1, 4, 14)});
  auto* graph_unused_outputs = monitoring::Counter<1>::New(
  @@ -72,8 +72,8 @@ auto* tf_data_bytes_fetched_counter = monitoring::Counter<0>::New(
  auto* tf_data_getnext_duration_counter = monitoring::Sampler<0>::New(
  {"/tensorflow/data/getnext_duration",
  "Microseconds spent fetching an element from tf.data Dataset iterator."},
  - // Power of 2 with bucket count 14 (256G)
  - {monitoring::Buckets::Exponential(1, 4, 20)});
  + // Power of 2 with bucket count 10 (1024 ms)
  + {monitoring::Buckets::Exponential(1, 2, 10)});
  auto* tf_data_elements_counter = monitoring::Counter<1>::New(
  "/tensorflow/data/elements", "tf.data elements", "name");
  