fix(o11y): composite tracer to process url changes (#12754)

Fixes finding from
#12730

Author: diegomarquezp

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

@@ -220,4 +220,11 @@ public void injectTraceContext(java.util.Map<String, String> carrier) {
       child.injectTraceContext(carrier);
     }
   }
+
+  @Override
+  public void requestUrlResolved(String requestUrl) {
+    for (ApiTracer child : children) {
+      child.requestUrlResolved(requestUrl);
+    }
+  }
 }

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

@@ -279,4 +279,12 @@ void testInjectTraceContext() {
     inOrder.verify(child1).injectTraceContext(carrier);
     inOrder.verify(child2).injectTraceContext(carrier);
   }
+
+  @Test
+  void testRequestUrlResolved() {
+    compositeTracer.requestUrlResolved("the-url");
+    InOrder inOrder = inOrder(child1, child2);
+    inOrder.verify(child1).requestUrlResolved("the-url");
+    inOrder.verify(child2).requestUrlResolved("the-url");
+  }
 }