Log vlog when null creds are returned

PiperOrigin-RevId: 805533615
diff --git a/src/core/credentials/transport/alts/alts_credentials.cc b/src/core/credentials/transport/alts/alts_credentials.cc
index bd3226f..4bfcda7 100644
--- a/src/core/credentials/transport/alts/alts_credentials.cc
+++ b/src/core/credentials/transport/alts/alts_credentials.cc
@@ -90,7 +90,7 @@
     const grpc_alts_credentials_options* options,
     const char* handshaker_service_url, bool enable_untrusted_alts) {
   if (!enable_untrusted_alts && !grpc_alts_is_running_on_gcp()) {
-    LOG(ERROR) << "ALTS creds ignored. Not running on GCP and untrusted ALTS "
+    VLOG(1) << "ALTS creds ignored. Not running on GCP and untrusted ALTS "
                   "is not enabled.";
     return nullptr;
   }
@@ -101,7 +101,7 @@
     const grpc_alts_credentials_options* options,
     const char* handshaker_service_url, bool enable_untrusted_alts) {
   if (!enable_untrusted_alts && !grpc_alts_is_running_on_gcp()) {
-    LOG(ERROR) << "ALTS server creds ignored. Not running on GCP and untrusted "
+    VLOG(1) << "ALTS server creds ignored. Not running on GCP and untrusted "
                   "ALTS is not enabled.";
     return nullptr;
   }
diff --git a/src/core/credentials/transport/tls/tls_credentials.cc b/src/core/credentials/transport/tls/tls_credentials.cc
index fe7e605..49f0fe9 100644
--- a/src/core/credentials/transport/tls/tls_credentials.cc
+++ b/src/core/credentials/transport/tls/tls_credentials.cc
@@ -154,7 +154,7 @@
 grpc_channel_credentials* grpc_tls_credentials_create(
     grpc_tls_credentials_options* options) {
   if (!CredentialOptionSanityCheck(options, true /* is_client */)) {
-    LOG(ERROR) << "TLS credentials options sanity check failed.";
+    VLOG(1) << "TLS credentials options sanity check failed.";
     return nullptr;
   }
   return new TlsCredentials(
@@ -164,7 +164,7 @@
 grpc_server_credentials* grpc_tls_server_credentials_create(
     grpc_tls_credentials_options* options) {
   if (!CredentialOptionSanityCheck(options, false /* is_client */)) {
-    LOG(ERROR) << "TLS server credentials options sanity check failed.";
+    VLOG(1) << "TLS server credentials options sanity check failed.";
     return nullptr;
   }
   return new TlsServerCredentials(