Update tracing in interop test

tonic-interop/src/lib.rs

@@ -11,6 +11,15 @@ pub mod pb {
 
 use std::{default, fmt, iter};
 
+pub fn trace_init() {
+    let sub = tracing_subscriber::FmtSubscriber::builder()
+        .with_env_filter(tracing_subscriber::filter::EnvFilter::from_default_env())
+        .finish();
+
+    let _ = tracing::subscriber::set_global_default(sub);
+    let _ = tracing_log::LogTracer::init();
+}
+
 pub fn client_payload(size: usize) -> pb::Payload {
     pb::Payload {
         r#type: default::Default::default(),