Polish "Add property for mongo auto-index creation"

See gh-16454

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoProperties.java

@@ -92,7 +92,7 @@ public class MongoProperties {
 	private Class<?> fieldNamingStrategy;
 
 	/**
-	 * Enables/disables auto-index creation.
+	 * Whether to enable auto-index creation.
 	 */
 	private Boolean autoIndexCreation;
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/mongo/MongoDataAutoConfigurationTests.java

@@ -135,12 +135,12 @@ public class MongoDataAutoConfigurationTests {
 	@Test
 	public void customAutoIndexCreation() {
 		this.contextRunner
-				.withPropertyValues("spring.data.mongodb.autoIndexCreation:true")
+				.withPropertyValues("spring.data.mongodb.autoIndexCreation:false")
 				.run((context) -> {
 					MongoMappingContext mappingContext = context
 							.getBean(MongoMappingContext.class);
 					assertThat(mappingContext.isAutoIndexCreation())
-							.isEqualTo(Boolean.TRUE);
+							.isEqualTo(Boolean.FALSE);
 				});
 	}