fix: post-merge compilation issue in showcase

Author: diegomarquezp

java-showcase/gapic-showcase/src/test/java/com/google/showcase/v1beta1/it/ITOtelTracing.java

@@ -237,8 +237,7 @@ void testTracing_retry_grpc() throws Exception {
             .setEndpoint("localhost:7469")
             .build();
 
-    SpanTracerFactory tracingFactory =
-        new SpanTracerFactory(new OpenTelemetryTraceManager(openTelemetrySdk));
+    SpanTracerFactory tracingFactory = new SpanTracerFactory(openTelemetrySdk);
 
     EchoStubSettings echoStubSettings =
         (EchoStubSettings)
@@ -310,8 +309,7 @@ void testTracing_retry_httpjson() throws Exception {
                     .build())
             .build();
 
-    SpanTracerFactory tracingFactory =
-        new SpanTracerFactory(new OpenTelemetryTraceManager(openTelemetrySdk));
+    SpanTracerFactory tracingFactory = new SpanTracerFactory(openTelemetrySdk);
 
     EchoStubSettings echoStubSettings =
         (EchoStubSettings)