Verify Pulsar consumer enum values as properties

When providing Pulsar consumer properties as Boot properties,
if there are enum values, verify that they are translated properly
as valid consumer properties.

spring-pulsar-spring-boot-autoconfigure/src/test/java/org/springframework/pulsar/autoconfigure/PulsarAutoConfigurationTests.java

@@ -21,6 +21,7 @@ import static org.mockito.Mockito.mock;
 
 import java.util.concurrent.TimeUnit;
 
+import org.apache.pulsar.client.api.SubscriptionInitialPosition;
 import org.apache.pulsar.client.api.interceptor.ProducerInterceptor;
 import org.assertj.core.api.InstanceOfAssertFactories;
 import org.junit.jupiter.api.Nested;
@@ -54,6 +55,7 @@ import org.springframework.pulsar.listener.DefaultPulsarMessageListenerContainer
  *
  * @author Chris Bono
  * @author Alexander Preuß
+ * @author Soby Chacko
  */
 @SuppressWarnings("unchecked")
 class PulsarAutoConfigurationTests {
@@ -139,6 +141,14 @@ class PulsarAutoConfigurationTests {
 						.isSameAs(consumerFactory));
 	}
 
+	@Test
+	void pulsarConsumerFactoryWithEnumPropertyValue() {
+		this.contextRunner.withPropertyValues("spring.pulsar.consumer.subscriptionInitialPosition=Earliest")
+				.run((context -> assertThat(context).hasNotFailed().getBean(PulsarConsumerFactory.class)
+						.extracting("consumerConfig").hasFieldOrPropertyWithValue("subscriptionInitialPosition",
+								SubscriptionInitialPosition.Earliest)));
+	}
+
 	@Test
 	void customPulsarListenerContainerFactoryIsRespected() {
 		PulsarListenerContainerFactory<DefaultPulsarMessageListenerContainer<String>> listenerContainerFactory = mock(