message: metrics: rename metric read_latency_hits_dist
  Thus to make it more suggestive
diff: @@ -596,7 +596,7 @@ pub struct BackendMetrics {
  read_cumulative_latency_millis_dist: [BasicMetric; BLOCK_READ_SIZES_MAX],
  read_count_block_size_dist: [BasicMetric; BLOCK_READ_SIZES_MAX],
  // Categorize metrics as per their latency and request size
  - read_latency_hits_dist: [[BasicMetric; READ_LATENCY_RANGE_MAX]; BLOCK_READ_SIZES_MAX],
  + read_latency_sizes_dist: [[BasicMetric; READ_LATENCY_RANGE_MAX]; BLOCK_READ_SIZES_MAX],
  }
  impl Metric for BasicMetric {
  @@ -680,7 +680,7 @@ impl BackendMetrics {
  let size_idx = request_size_index(size);
  self.read_cumulative_latency_millis_dist[size_idx].add(elapsed);
  self.read_count_block_size_dist[size_idx].inc();
  - self.read_latency_hits_dist[size_idx][lat_idx].inc();
  + self.read_latency_sizes_dist[size_idx][lat_idx].inc();
  }
  }
  