Use Jackson ObjectMapper from AutoConfiguration

- For the message converters that use Jackson ObjectMapper, autowire the ObjectMapper from JacksonAutoConfiguration
   - This will allow configuration of ObjectMapper using boot configuration properties `JacksonProperties`

 - Add test

This resolves #466

spring-cloud-stream-integration-tests/src/test/java/org/springframework/cloud/stream/config/MessageChannelConfigurerTests.java

@@ -16,6 +16,7 @@
 package org.springframework.cloud.stream.config;
 
 import static org.hamcrest.Matchers.instanceOf;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
@@ -39,6 +40,9 @@ import org.springframework.messaging.MessagingException;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 import org.springframework.tuple.Tuple;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+
 /**
  * @author Ilayaperumal Gopinathan
  */
@@ -49,6 +53,9 @@ public class MessageChannelConfigurerTests {
 	@Autowired @Bindings(TestSink.class)
 	private Sink testSink;
 
+	@Autowired
+	private ObjectMapper objectMapper;
+
 	@Test
 	public void testMessageConverterConfigurer() throws Exception {
 		final CountDownLatch latch = new CountDownLatch(1);
@@ -66,6 +73,12 @@ public class MessageChannelConfigurerTests {
 		assertTrue(latch.await(10, TimeUnit.SECONDS));
 		testSink.input().unsubscribe(messageHandler);
 	}
+
+	@Test
+	public void testObjectMapperConfig() {
+		assertNotNull( "ObjectMapper should exist", objectMapper);
+		assertTrue("SerializationFeature 'WRITE_DATES_AS_TIMESTAMPS' should be disabled", !objectMapper.getSerializationConfig().isEnabled(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS));
+	}
 	
 	@EnableBinding(Sink.class)
 	@EnableAutoConfiguration

spring-cloud-stream-integration-tests/src/test/resources/org/springframework/cloud/stream/config/channel/sink-channel-configurers.properties

@@ -1,2 +1,3 @@
 spring.cloud.stream.bindings.input.destination=configure1
 spring.cloud.stream.bindings.input.contentType=application/x-spring-tuple
+spring.jackson.serialization.WRITE_DATES_AS_TIMESTAMPS:false