refactor(o11y): make OpenTelemetryMetricsFactory mutable and remove internal annotations

Author: blakeli0

sdk-platform-java/gax-java/gax/src/main/java/com/google/api/gax/tracing/OpenTelemetryMetricsFactory.java

@@ -29,17 +29,13 @@
  */
 package com.google.api.gax.tracing;
 
-import com.google.api.core.BetaApi;
-import com.google.api.core.InternalApi;
 import io.opentelemetry.api.OpenTelemetry;
 
 /**
  * A {@link ApiTracerFactory} to build instances of {@link OpenTelemetryMetricsTracer}.
  *
  * <p>This class is expected to be initialized once during client initialization.
  */
-@BetaApi
-@InternalApi
 public class OpenTelemetryMetricsFactory implements ApiTracerFactory {
 
   private ApiTracerContext clientLevelTracerContext;

sdk-platform-java/gax-java/gax/src/test/java/com/google/api/gax/tracing/OpenTelemetryMetricsFactoryTest.java

@@ -69,17 +69,16 @@ void newTracerWithSpanName_shouldCreateBaseTracer_ifMetricsRecorderIsNull() {
 
   @Test
   void newTracerWithApiTracerContext_shouldMergeApiTracerContext() {
-    ApiTracerContext clientLevelTracerContext = mock(ApiTracerContext.class, RETURNS_DEEP_STUBS);
-    ApiTracerContext methodLevelTracerContext = mock(ApiTracerContext.class);
-    when(clientLevelTracerContext.libraryMetadata().artifactName()).thenReturn("gax-java");
-    when(clientLevelTracerContext.libraryMetadata().isEmpty()).thenReturn(false);
-    when(clientLevelTracerContext.merge(methodLevelTracerContext))
-        .thenReturn(clientLevelTracerContext);
-
-    tracerFactory.withContext(clientLevelTracerContext);
-    ApiTracer actual = tracerFactory.newTracer(mock(ApiTracer.class), methodLevelTracerContext);
+    LibraryMetadata metadata =
+        LibraryMetadata.newBuilder().setArtifactName("gax-java").setVersion("1.0").build();
+    ApiTracerContext clientLevelTracerContext =
+        ApiTracerContext.newBuilder().setLibraryMetadata(metadata).build();
+    ApiTracerContext methodLevelTracerContext =
+        ApiTracerContext.newBuilder().setLibraryMetadata(LibraryMetadata.empty()).build();
+    
+    ApiTracerFactory factoryWithContext = tracerFactory.withContext(clientLevelTracerContext);
+    ApiTracer actual = factoryWithContext.newTracer(mock(ApiTracer.class), methodLevelTracerContext);
 
-    verify(clientLevelTracerContext).merge(methodLevelTracerContext);
     assertThat(actual).isInstanceOf(OpenTelemetryMetricsTracer.class);
   }