Remove irrelevant comments from metric name field (open-telemetry#512)

opentelemetry/proto/metrics/v1/metrics.proto

@@ -166,7 +166,9 @@ message ScopeMetrics {
 // when the start time is truly unknown, setting StartTimeUnixNano is
 // strongly encouraged.
 message Metric {
-  // name of the metric, including its DNS name prefix. It must be unique.
+  reserved 4, 6, 8;
+
+  // name of the metric.
   string name = 1;
 
   // description of the metric, which can be used in documentation.
@@ -536,7 +538,7 @@ message ExponentialHistogramDataPoint {
   // doing so.  This is specifically to enforce compatibility w/ OpenMetrics,
   // see: https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#histogram
   optional double sum = 5;
-  
+
   // scale describes the resolution of the histogram.  Boundaries are
   // located at powers of the base, where:
   //
@@ -574,7 +576,7 @@ message ExponentialHistogramDataPoint {
   // of counts.
   message Buckets {
     // Offset is the bucket index of the first entry in the bucket_counts array.
-    // 
+    //
     // Note: This uses a varint encoding as a simple form of compression.
     sint32 offset = 1;
 
@@ -588,7 +590,7 @@ message ExponentialHistogramDataPoint {
     // especially zeros, so uint64 has been selected to ensure
     // varint encoding.
     repeated uint64 bucket_counts = 2;
-  } 
+  }
 
   // Flags that apply to this specific data point.  See DataPointFlags
   // for the available flags and their meaning.