Polish "Add Duration support in /configprops endpoint"

Closes gh-16539

Author: snicoll

spring-boot-project/spring-boot-actuator/pom.xml

@@ -21,6 +21,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.datatype</groupId>
+			<artifactId>jackson-datatype-jsr310</artifactId>
+		</dependency>
 		<!-- Optional -->
 		<dependency>
 			<groupId>com.fasterxml.jackson.core</groupId>