update cr comments

Author: xiazhvera

src/native/iot_device_sdk_metrics.c

@@ -50,13 +50,12 @@ struct aws_mqtt_iot_metrics_java_jni *aws_mqtt_iot_metrics_java_jni_create_from_
             s_iot_device_sdk_metrics_string,
             "library name",
             &java_metrics->library_name_buf,
-            &java_metrics->library_name_cursor,
+            &java_metrics->metrics.library_name,
             false,
             NULL) == AWS_OP_ERR) {
         AWS_LOGF_ERROR(AWS_LS_MQTT_GENERAL, "IoTDeviceSDKMetrics create_from_java: No library name found");
         goto on_error;
     }
-    java_metrics->metrics.library_name = java_metrics->library_name_cursor;
 
     return java_metrics;
 
@@ -65,12 +64,3 @@ struct aws_mqtt_iot_metrics_java_jni *aws_mqtt_iot_metrics_java_jni_create_from_
     aws_mqtt_iot_metrics_java_jni_destroy(env, allocator, java_metrics);
     return NULL;
 }
-
-struct aws_mqtt_iot_metrics *aws_mqtt_iot_metrics_java_jni_get_metrics(
-    struct aws_mqtt_iot_metrics_java_jni *java_metrics) {
-    if (java_metrics) {
-        return &java_metrics->metrics;
-    } else {
-        return NULL;
-    }
-}

src/native/iot_device_sdk_metrics.h

@@ -12,7 +12,6 @@
 struct aws_mqtt_iot_metrics_java_jni {
     struct aws_mqtt_iot_metrics metrics;
     struct aws_byte_buf library_name_buf;
-    struct aws_byte_cursor library_name_cursor;
 };
 
 void aws_mqtt_iot_metrics_java_jni_destroy(
@@ -25,7 +24,4 @@ struct aws_mqtt_iot_metrics_java_jni *aws_mqtt_iot_metrics_java_jni_create_from_
     struct aws_allocator *allocator,
     jobject java_iot_device_sdk_metrics);
 
-struct aws_mqtt_iot_metrics *aws_mqtt_iot_metrics_java_jni_get_metrics(
-    struct aws_mqtt_iot_metrics_java_jni *java_metrics);
-
 #endif /* AWS_JNI_IOT_DEVICE_SDK_METRICS_H */

src/native/mqtt_connection.c

@@ -1129,6 +1129,11 @@ JNIEXPORT void JNICALL Java_software_amazon_awssdk_crt_mqtt_MqttClientConnection
     struct aws_mqtt_iot_metrics_java_jni *iot_metrics_java_jni =
         aws_mqtt_iot_metrics_java_jni_create_from_java(env, aws_jni_get_allocator(), jni_metrics);
 
+    if (iot_metrics_java_jni == NULL) {
+        AWS_LOGF_DEBUG(AWS_LS_MQTT_CLIENT, "MqttClientConnection failed to create metrics.");
+        return;
+    }
+
     if (aws_mqtt_client_connection_set_metrics(connection->client_connection, &iot_metrics_java_jni->metrics)) {
         int error = aws_last_error();
         AWS_LOGF_DEBUG(