Use @ConditionalOnProperty where possible

src/main/java/org/springframework/cloud/client/CommonsClientAutoConfiguration.java

@@ -1,10 +1,12 @@
 package org.springframework.cloud.client;
 
+import java.util.List;
+
 import org.springframework.boot.actuate.health.HealthAggregator;
 import org.springframework.boot.actuate.health.HealthIndicator;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.cloud.client.discovery.DiscoveryClient;
 import org.springframework.cloud.client.discovery.DiscoveryClientHealthIndicator;
 import org.springframework.cloud.client.discovery.DiscoveryCompositeHealthIndicator;
@@ -13,8 +15,6 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.annotation.Order;
 
-import java.util.List;
-
 /**
  * @author Spencer Gibb
  */
@@ -25,7 +25,7 @@ public class CommonsClientAutoConfiguration {
 
 	@Configuration
 	@ConditionalOnBean(DiscoveryClient.class)
-	@ConditionalOnExpression("${spring.cloud.discovery.enabled:true}")
+	@ConditionalOnProperty(value = "spring.cloud.discovery.enabled", matchIfMissing = true)
 	protected static class HealthConfiguration {
 		@Bean
 		public DiscoveryClientHealthIndicator instancesHealthIndicator(DiscoveryClient discoveryClient) {

src/main/java/org/springframework/cloud/client/discovery/NoopDiscoveryClientConfiguration.java

@@ -23,8 +23,8 @@ import javax.annotation.PostConstruct;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.web.ServerProperties;
 import org.springframework.boot.context.embedded.EmbeddedServletContainer;
 import org.springframework.boot.context.embedded.EmbeddedWebApplicationContext;
@@ -44,7 +44,7 @@ import org.springframework.core.env.Environment;
 @Configuration
 @EnableConfigurationProperties
 @ConditionalOnMissingClass(name = "com.netflix.discovery.EurekaClientConfig")
-@ConditionalOnExpression("!${eureka.client.enabled:false}")
+@ConditionalOnProperty(value = "eureka.client.enabled", havingValue = "false")
 public class NoopDiscoveryClientConfiguration implements ApplicationListener<ContextRefreshedEvent> {
 
 	private static final Logger logger = LoggerFactory