chore(instrumentation-aws-sdk): update metric names to semconv METRIC_* exports (#3126)

Author: trentm

packages/instrumentation-aws-sdk/src/semconv.ts

@@ -601,3 +601,11 @@ export const GEN_AI_TOKEN_TYPE_VALUE_INPUT = 'input' as const;
  * @experimental This enum value is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
  */
 export const GEN_AI_TOKEN_TYPE_VALUE_OUTPUT = 'output' as const;
+
+/**
+ * Number of input and output tokens used.
+ *
+ * @experimental This metric is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
+ */
+export const METRIC_GEN_AI_CLIENT_TOKEN_USAGE =
+  'gen_ai.client.token.usage' as const;

packages/instrumentation-aws-sdk/src/services/bedrock-runtime.ts

@@ -40,6 +40,7 @@ import {
   GEN_AI_SYSTEM_VALUE_AWS_BEDROCK,
   GEN_AI_TOKEN_TYPE_VALUE_INPUT,
   GEN_AI_TOKEN_TYPE_VALUE_OUTPUT,
+  METRIC_GEN_AI_CLIENT_TOKEN_USAGE,
 } from '../semconv';
 import {
   AwsSdkInstrumentationConfig,
@@ -62,7 +63,7 @@ export class BedrockRuntimeServiceExtension implements ServiceExtension {
 
   updateMetricInstruments(meter: Meter) {
     // https://opentelemetry.io/docs/specs/semconv/gen-ai/gen-ai-metrics/#metric-gen_aiclienttokenusage
-    this.tokenUsage = meter.createHistogram('gen_ai.client.token.usage', {
+    this.tokenUsage = meter.createHistogram(METRIC_GEN_AI_CLIENT_TOKEN_USAGE, {
       unit: '{token}',
       description: 'Measures number of input and output tokens used',
       valueType: ValueType.INT,