update examples to support Gradle run target (#168)

Author: ianbotsf

examples/dynamodb-movies/build.gradle.kts

@@ -1,5 +1,10 @@
 plugins {
     kotlin("jvm")
+    application
+}
+
+application {
+    mainClass.set("aws.sdk.kotlin.example.MainKt")
 }
 
 val awsSdkKotlinVersion: String by project

examples/s3-media-ingestion/build.gradle.kts

@@ -1,5 +1,10 @@
 plugins {
     kotlin("jvm")
+    application
+}
+
+application {
+    mainClass.set("aws.sdk.kotlin.example.MainKt")
 }
 
 val awsSdkKotlinVersion: String by project

examples/s3-media-ingestion/src/main/kotlin/Main.kt renamed to examples/s3-media-ingestion/src/main/kotlin/aws/sdk/kotlin/example/Main.kt

@@ -2,6 +2,8 @@
  * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
  * SPDX-License-Identifier: Apache-2.0.
  */
+package aws.sdk.kotlin.example
+
 import aws.sdk.kotlin.services.s3.S3Client
 import aws.sdk.kotlin.services.s3.model.*
 import kotlinx.coroutines.flow.*