chore(gax): deprecate ApiTracer.inScope()

Author: jinseopkim0

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

@@ -52,7 +52,11 @@ public interface ApiTracer {
    * Asks the underlying implementation to install itself as a thread local. This allows for interop
    * between clients using gax and external resources to share the same implementation of the
    * tracing. For example OpenCensus will install a thread local that can read by the GRPC.
+   *
+   * @deprecated Scope management is handled internally by OpenTelemetry tracer implementations.
    */
+  @Deprecated
+  @ObsoleteApi("Scope management is handled internally by OpenTelemetry tracer implementations")
   default Scope inScope() {
     return () -> {
       // noop

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

@@ -61,6 +61,8 @@ public static ApiTracer getInstance() {
   }
 
   @Override
+  @Deprecated
+  @ObsoleteApi("Scope management is handled internally by OpenTelemetry tracer implementations")
   public Scope inScope() {
     return NOOP_SCOPE;
   }

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

@@ -30,6 +30,7 @@
 package com.google.api.gax.tracing;
 
 import com.google.api.core.InternalApi;
+import com.google.api.core.ObsoleteApi;
 import com.google.common.collect.ImmutableList;
 import java.util.ArrayList;
 import java.util.List;
@@ -52,6 +53,8 @@ public CompositeTracer(List<ApiTracer> children) {
   }
 
   @Override
+  @Deprecated
+  @ObsoleteApi("Scope management is handled internally by OpenTelemetry tracer implementations")
   public Scope inScope() {
     final List<Scope> childScopes = new ArrayList<>(children.size());