Add AWS Lambda example (#986)

JAVA-4474

Author: jyemin

driver-sync/build.gradle

@@ -27,6 +27,8 @@ dependencies {
     testImplementation project(':bson').sourceSets.test.output
     testImplementation project(':driver-core').sourceSets.test.output
     testRuntimeOnly project(path: ':driver-core', configuration: 'consumableTestRuntimeOnly')
+
+    testImplementation('com.amazonaws:aws-lambda-java-core:1.2.1')
 }
 
 sourceSets {

driver-sync/src/examples/documentation/ExampleAwsLambdaHandler.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2008-present MongoDB, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package documentation;
+
+import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.RequestHandler;
+import com.mongodb.client.MongoClient;
+import com.mongodb.client.MongoClients;
+import org.bson.Document;
+
+// Start AWS Lambda Example 1
+public class ExampleAwsLambdaHandler implements RequestHandler<String, String> {
+    private final MongoClient client;
+
+    public ExampleAwsLambdaHandler() {
+        client = MongoClients.create(System.getenv("MONGODB_URI"));
+    }
+
+    @Override
+    public String handleRequest(final String input, final Context context) {
+        return client.getDatabase("admin").runCommand(new Document("ping", 1)).toJson();
+    }
+}
+// End AWS Lambda Example 1