Review conditions of ElasticsearchHealthIndicatorAutoConfiguration

Closes gh-12249

Author: snicoll

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/elasticsearch/ElasticsearchHealthIndicatorAutoConfiguration.java

@@ -32,6 +32,7 @@
 import org.springframework.boot.autoconfigure.AutoConfigureBefore;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchAutoConfiguration;
 import org.springframework.boot.autoconfigure.elasticsearch.jest.JestAutoConfiguration;
@@ -55,6 +56,7 @@
 public class ElasticsearchHealthIndicatorAutoConfiguration {
 
 	@Configuration
+	@ConditionalOnClass(Client.class)
 	@ConditionalOnBean(Client.class)
 	@EnableConfigurationProperties(ElasticsearchHealthIndicatorProperties.class)
 	static class ElasticsearchClientHealthIndicatorConfiguration extends
@@ -87,6 +89,7 @@ protected ElasticsearchHealthIndicator createHealthIndicator(Client client) {
 	}
 
 	@Configuration
+	@ConditionalOnClass(JestClient.class)
 	@ConditionalOnBean(JestClient.class)
 	static class ElasticsearchJestHealthIndicatorConfiguration extends
 			CompositeHealthIndicatorConfiguration<ElasticsearchJestHealthIndicator, JestClient> {